Global Marine Ecological Status Report
The ecological status of the marine pelagic environment based on
observations from the global Continuous Plankton Recorder Surveys
Global Alliance of Continuous Plankton Recorder Surveys (GACS)
2010/2011
Citation: Edwards, M., Helaouet, P. , Johns, D.G., Batten, S., Beaugrand, G., Chiba, S., Flavell,
M., Head, E., Hosie, G., Richardson, A.J., Takahashi, K., Verheye. H.M., Ward, P. & Wootton,
M. 2012. Global Marine Ecological Status Report: results from the global CPR survey
2010/2011. SAHFOS Technical Report, 9: 1-40. Plymouth, U.K. ISSN 1744-0750
Lead author, design & main images: M. Edwards
Contributing authors: S. Batten, S. Chiba, E. Head, G. Hosie, A.J. Richardson, K. Takahashi,
H.M. Verheye, P. Ward and M. Wootton.
Statistical analysis and data processing: P. Helaouet, D. Johns, M. Flavell and G. Beaugrand
Printer: Kingfisher, Totnes, Devon, UK
Published by: Sir Alister Hardy Foundation for Ocean Science. ©SAHFOS 2012
ISSN No: ISSN 1744-0750
Contents
2..........................................................................Introduction
4..........................................................................Global research highlights
7..........................................................................Global environmental change
10........................................................................Global CPR observations
21........................................................................Ecoregional assessment of the North Atlantic
28........................................................................Applied ecological indicators of the NE Atlantic
Marine climate change impacts
Marine biodiversity and invasive species
Marine ecosystem health and environmental health
Ocean acidification
Summary for policy makers
36...........................................................................Bibliography
Global Alliance of Continuous
Plankton Recorder Surveys
(GACS)
CPR samples in the Northern and Southern
hemispheres. Courtesy of Google Earth.
The establishment of a global network of CPR surveys has long been a vision of the Sir Alister
Hardy Foundation for Ocean Science (SAHFOS) and finally got underway in 2011. Going Global was
also a vision shared by the heads of other regional surveys around the globe, who enthusiastically
agreed to form the Global Alliance of CPR Surveys (GACS). It seemed appropriate then, during the
celebrations in Plymouth, UK. in September 2011 that marked the 80th Anniversary of the start
of the North Sea CPR tows, the heads of the nine regional CPR surveys should meet to discuss the
formation of GACS. Joining the group were a number of representatives from the Global Ocean
Observing System (GOOS) programme of the Intergovermental Oceanographic Commission (IOC)
of UNESCO, the Partnership for the Observation of the Global Oceans (POGO) and the North Pacific
Marine Science Organisation known as PICES. They provided invaluable advice to help set up GACS
and also witnessed the signing of the Memorandum of Understanding by the founding GACS
partners.
The general goal of GACS is to understand changes in plankton biodiversity at ocean basin scales
through a global alliance of CPR surveys. By “understand” we mean characterise, analyse and
interpret. GACS has a number of specific aims which include:
• development of a global CPR database
• production of a regular Global Marine Status Report (this document)
• ensuring common standards and methodologies are maintained
• providing an interface for plankton biodiversity with other global ocean observation
programmes
• to set up and maintain a website for publicity and data access
• to facilitate new surveys and develop capacity building procedures
• to facilitate secondments of CPR scientists between GACS institutions
GACS brings together the expertise of approximately 50 plankton specialists, scientists, technicians
and administrators from 12 laboratories around the world, towing a common and consistent
sampling tool, the CPR, from about 50 vessels. Working together, pooling our data and resources,
was considered essential in order to understand the effects of environmental changes on plankton
Participants at the first GACS meeting held at SAHFOS in Plymouth 2011
biodiversity at a global level. Numerous local and regional monitoring and observational
programmes have been established in the past, but to date we have lacked a holistic
perspective on plankton biodiversity in response to global events such as global warming
and ocean acidification. GACS will provide that perspective using CPR data, a well recognised
and standardised methodology. It will also allow us to assess changes and events at a local or
regional level in a world-wide context. At the heart of GACS is the development of the global
database of CPR data that will allow us to make such assessments of local, regional and global
changes. Subsequently, an important product of GACS will be the production of a regular
Ecological Status Report for global plankton biodiversity.
CPR surveys are now well established in the North Sea, North Atlantic, North Pacific and
Southern Ocean. New surveys are underway in Australian, New Zealand, Japanese and South
African waters with a Brazilian survey under development. These surveys provide coverage
of much of the world’s oceans. However, there are still vast areas of the mid-Atlantic, Pacific
and Indian Oceans where there are no sustained plankton monitoring. One of the long-term
challenges will be filling these gaps.
A Board of Governance has been established, comprising the regional heads of CPR Surveys:
Dr Graham Hosie, SCAR Southern Ocean CPR Survey (Chair)
Dr Sonia Batten, North Pacific CPR (Vice-Chair)
Dr Sanae Chiba, Japan JAMSTEC CPR
Prof. Martin Edwards, (P.I.) SAHFOS
Prof. Mitsuo Fukuchi, Japan NIPR CPR
Dr Julie Hall, New Zealand CPR
Assoc. Prof. Anthony Richardson, Australian CPR (AusCPR)
Dr Chris Melrose, Narrangansett USA CPR
Prof. Nick Owens (Director) SAHFOS
Prof. Erik Muxagata, Brazil
Dr Hans Verheye, South Africa CPR
Prof. Peter Burkill, ex officio
Global marine ecological status report
At the base of the marine foodweb, the free floating plant life of the sea (phytoplankton)
provide food for the animal plankton (zooplankton) which in turn provide food for many
other marine organisms. The carrying capacity of marine ecosystems in terms of the size of
fish resources and recruitment to individual stocks as well as the abundance of marine wildlife
(e.g. seabirds and marine mammals) is highly dependent on variations in the abundance,
timing and composition of the plankton.
These organisms also play a crucial role in climate change through the export of the
important greenhouse gas CO2 to the deep ocean by carbon sequestration in what is known
as the ‘biological pump’. Without this process concentrations of CO2 would be much higher
in the atmosphere and the climate of the world would be much warmer. Apart from playing
a fundamental role in the earth’s climate system and in marine foodwebs, plankton are also
highly sensitive indicators of environmental change and provide essential information on the
‘ecological health’ of our seas.
The following report provides indicators for the status of the global marine environment and
provides information for important marine management issues such as climate warming
impacts, biodiversity, pollution and fisheries.
Working groups are being developed and will address the formation of the global CPR
database, and maintaining standards and methodologies. Supporting all this are also
a number of SAHFOS staff involved with secretariat support, database development,
collaboration, training and publicity.
In order to keep scientists, governments and the public informed of GACS activities the GACS
website has been established at www.globalcpr.org, which provides information about GACS,
the member surveys and news of events. Regular newsletters will be produced and the first
newsletter has already been distributed. It is exciting times ahead for GACS and for studying
and monitoring plankton biodiversity at a global scale.
GACS/status
3
Global research highlights
Fish larvae atlas of the NE Atlantic
Results from the Continuous Plankton Recorder survey 1948-2005
Fish larvae atlas of the NE
Atlantic
Sir Alister Hardy Foundation for Ocean Science
Monitoring the health of the oceans since 1931
Retrospective analysis of fish larvae
recorded by the CPR survey has
produced new spatial and temporal
records of 70 species of fish larvae over
the last 60 years.
Edwards, M., Helaouet, P., Halliday. N.,
Beaugrand, G., Fox, C., Johns, D.G., Licandro,
P., Lynam, C., Pitois, S., Stevens, D., Coombs, S
& Fonseca, L. 2011. Fish Larvae Atlas of the NE
Atlantic. Results from the Continuous Plankton
Recorder survey 1948-2005. Sir Alister Hardy
Foundation for Ocean Science. 22p. Plymouth,
U.K. ISBN No: 978-0-9566301-2-7
Marine pathogens and vibrio
As sea surface temperatures increase, predictions favour an increase in the
number and range of pathogenic micro-organisms. Such changes are difficult
to determine over short time periods that cannot separate short-term variations
from climate change trends. In a unique long-term time study,Vezzulli et al.
(2011) investigated the spread of the pathogenic bacteria, Vibrio, the causative
agent of cholera in the North Sea over 54 years, between 1961-2005, and
revealed that Vibrio bacteria is increasing in this region. The increase was
related to rising temperatures in the North Sea.
Vezzulli, L., Brettar, I., Pezzati, E., Reid, P.C., Colwell, R.R., Höfle, M.G. and Pruzzo, C., 2011. Longterm effects of ocean warming on the prokaryotic community: evidence from the vibrios. The
ISME Journal: Multidisciplinary Journal of Microbial Ecology, 6: 21-30.
Climate change and
phytoplankton abundance
Hinder, S.L., Hays,G., Edwards, M., Emily C.
Roberts, E.C., Walne, A.W. & Gravenor, M.B. 2012.
Changes in marine dinoflagellate and diatom
abundance under climate change. Nature
Climate Change, DOI: 10.1038/NCLIMATE1388.
global/status
4
CPR detects the red-tide
dinoflagellate Noctiluca
scintillans in the Southern
Ocean for the first time
Mcleod, D.J., Hallegraeff, G.M., Hosie, G.W. & Richardson,
A.J. 2012.Climate-driven range expansion of the red-tide
dinoflagellate Noctiluca scintillans into the Southern
Ocean. J. Plankton Res : fbr112v1-fbr112.
Sir Alister Hardy Foundation for Ocean Science
Northward movement of NE Pacific copepods
and climate variability
Batten, S.D. and Walne, A.W., 2011. Variability in northwards extension of warm water
copepods in the NE Pacific. Journal of Plankton Research, 33: 1643– 1653.
Climate Change and European
Marine Ecosystem Research
European Commission’s Seventh Framework Programme: Climate Change and European Marine Ecosystem Research (CLAMER)
Sir Alister Hardy Foundation for Ocean Science
Restructuring of marine foodwebs caused
by overfishing
Overfishing of large-bodied benthic fishes and their subsequent
population collapses on the Scotian Shelf of Canada’s east
coast, and elsewhere resulted in the restructuring of entire food
webs now dominated by planktivorous, forage fish species and
macroinvertebrates.
Chris Reid, Glynn Gorick & Martin Edwards
Major policy document on marine
ecosystem research
Frank, K.T., Petrie, B., Fisher, J.A.D. and Leggett, W.C., 2011. Transient dynamics
of an altered large marine ecosystem. Nature, 477: 86-89.
Reid, P.C., Gorick, G. & Edwards, M. 2011. Climate change and
European Marine Ecosystem Research. 53p. Sir Alister Hardy
Foundation for Ocean Science, Plymouth, UK.
GACS/status
5
Monitoring marine biodiversity from genes to ecosystems
PHYSICAL MEASUREMENTS 1991-
BIOLOGICAL MEASUREMENTS 1931-
Light microscopy
Genetic analysis
Instruments placed in rear of CPR or onboard vessel
Mega and macro
plankton
(1) Continuous Plankton Recorder (CPR)
Longest sustained marine biological time-series in the
world (1931-). Routine analysis of ~500 plankton taxa.
1.
Multi-decadal sample and molecular archive at oceanbasin scale (1950-).
Meso and microplankton
Upto 500 species routinely
recorded making the CPR
database one of the richest
ecological datasets in the
world
3.
Nano and pico-plankton
Placed in rear of CPR
Timed water samples and
other measurements along
CPR route
2.
Flow cytometry
(example)
(2) Water and Microplankton Sampler (WaMS)
Aimed at smaller size-fraction nano and pico
plankton community.
Sea surface temperature, salinity, depth and chlorophyll (1991-)
pCO2 (2002-)
Microplastics (2004-)
Other measurements: Dissolved Inorganic Carbon, Alkalinity,
Oxygen content, nutrients.
Flow cytometry (2010-)
Molecular probes and barcoding (2010-)
Harmful Algal Bloom microarrays (2010-)
global/status
(3) Physical measurements
6
Sir Alister Hardy Foundation for Ocean Science
Global sea surface
temperatures
Global environmental change
Arctic and Antarctic ice
GACS/status
7
Global environmental change
Global Sea Surface Temperatures
Over the last few decades the North Atlantic temperature has continued to
show a strong increase similar to the pattern found in Northern Hemisphere
temperatures. The temperature increase is currently mainly associated with
increasing CO2 input into the atmosphere from anthropogenic sources. The last
few years, however, have seen a slight decline in temperature compared to the
early and mid 2000s. Apart from external climate warming there are a number of
natural oscillations. In the Atlantic the most important oscillations are the Atlantic
Multidecadal lndex (AMO) and the North Atlantic Oscillation (NAO). The NAO is
responsible, particularly during the winter months, for much of the variability
of weather in the North Atlantic region, affecting wind speed and prevailing
direction, changes in SST and moisture distribution and the intensity, number
and track of storms.
Sea surfce temperature in the oceanic north east Pacific is strongly influenced by the Pacific Decadal
Oscillation, being cool (warm) in negative (positive) PDO phases. The western oceanic North Pacific
generally shows an opposite SST pattern to the east. ENSO events (El Nino Southern Oscillation) can
also be apparent in the northeast Pacific, such as the warm conditions following the strong El Nino of
1998. Since about the mid 1980s the oscillations between warm and cool PDO phases have occurred
with increased frequency, now switching phase roughly every 4 to 5 years. The most recent negative
PDO period began in 2007, resulting in cooler than average conditions in the east, and positive
anomalies in the west. In fact the Gulf of Alaska was cooler in 2008 than at any time since the early
1970s and is still cool.
During the last couple of years the NAO has been uncharacteristically in a
very low negative phase contributing to the very cold winters experienced in
Northern Europe during 2009/2010 and 2010/2011 reflected in below average
SST in the NE Atlantic. While Northern Europe was experiencing cold weather
areas in Greenland, the Canadian Arctic and the Labrador Sea hit record
temperatures in 2010 resulting in extended melt periods. Overall, natural
climate variability in the North Atlantic can account for approximately half ofthe
temperature change experienced in the North Atlantic over the last 50 years. All
these climate indices have been implicated in the changing ecology of the North
Atlantic over the last 50 years including rapid biogeographical and phenological
shifts in the plankton as well as whole ecosystem shifts.
The SCAR Antarctic Climate Change and the Environment (ACCE) Report
identified the Antarctic/Southern Ocean region as particularly vulnerable to the
impacts of climate change; warming oceans, changing circulation, diminishing
sea-ice habitat and ocean acidification. The Southern Ocean has already
experienced substantial warming (Aoki et al., 2003; ; Gille 2002). This warming
has not been uniform. Some areas such as the western Antarctic Peninsula (WAP)
have recorded significant increase in water temperature caused by Circumpolar
Deep Water being pushed up onto the shelf (Dinniman et al. 2012). This has
led to a decline in sea-ice, a regime shift in the phytoplankton, a change from a
krill-centric to copepod dominated food web and changes in abundance and
distribution of Adelie and Gentoo penguins (Dinniman et al. 2012; Hofmann et
al., 2008; Montes-Hugo et al. 2009).
global/status
Fig. 1. Global Sea Surface Temperature anomalies for 2010 minus the long-term
average 1960-2010. Sea surface temperature data were obtained from the Met Office
Hadley Centre (http://www.metoffice.gov.uk/).
8
Sir Alister Hardy Foundation for Ocean Science
Arctic and Antarctic ice
The thickness and areal coverage of summer ice in the Arctic have been decreasing at an increasingly
rapid rate over the last two decades, to reach the lowest recorded extent in September 2007 (in
respect to1978-2010). In the spring following the unusually large ice free period in 1998 large
numbers of the Pacific diatom Neodenticula seminae were found in samples taken by the CPR survey
in the Labrador Sea in the North Atlantic. N. seminae is an abundant member of the phytoplankton in
the subpolar North Pacific and has a well defined palaeo history based on deep sea cores. According
to the palaeo evidence and modern surface sampling in the North Atlantic since 1948 this was the
first record of this species in the North Atlantic for at least 800,000 years. 2010 saw the third lowest
recorded sea ice extent since 1979.
(a)
In the southern hemisphere the frontal zones of the Antarctic Circumpolar Current (ACC) are moving
south. The Bellingshausen Sea in the Pacific sector has recorded the fastest ice retreat, whereas
other regions have in particular the Ross Sea has recorded an increase in sea ice extent in the short
term. In the long term, the ACCE Report predicts an overall loss of sea-ice of 33% during the 21st
Century. Substantial sea ice loss has already occurred during the 1960’s (de la Mare 1997, 2009).
Atkinson et al. (2004) have reported a substantial decline in the abundance and distribution of
Antarctic krill Euphausia superba, a major keystone in the Antarctic food web and sea-ice habitat. This
decline is likely to be due to the decrease in sea-ice extent. At the same time salps have increased
their abundance in the region north of the sea-ice / krill habitat. Further sea-ice loss, warming and
southward movements of the fronts is expected to see a contraction of plankton southward. There is
a limit to southward movement due to the presence of the continent. For example, the coastal ice krill
Euphausia crystallorophias, which prefers sub-zero water will have nowhere to retreat.
(b)
Fig. 2 (a) Sea Ice extent for summer 2010. Orange line is the median from 1979-2000.
Source: National Snow and Ice Data Center. (b) Sea ice concentration anomalies for
the Northern (September) and Southern Hemispheres (March). 2010 anomalies for
the Northern Hemisphere were -1.8 million km2 below the long-term mean and +0.1
million km2 for the Southern Hemisphere. Source: National Snow and Ice Data Center.
GACS/status
9
Global CPR observations
global/status
10
Sir Alister Hardy Foundation for Ocean Science
Global CPR observations
The Southern Ocean
and 1970s (de la Mare, 2009). Since the late 1970s there has been
a slight but statistically significant increase in sea-ice overall of
about 0.9% per decade, higher in the Ross Sea of 4.2% but there
has been a substantial decline in sea-ice in the neighbouring
Amundsen and Bellingshausen Seas area of 5.7% per decade. In
the long term, it is predicted that there will be an overall decline
of winter sea-ice extent and volume of 24 to 34 % by the end of
the 21st Century. Further sea-ice loss, warming and southward
movements of the fronts is expected to see a contraction of
plankton southward. There is a limit to southward movement due
to the presence of the continent. For example, the coastal ice kill
Euphausia crystallorophias, which prefers sub-zero water will have
nowhere to retreat.
Graham Hosie
Australian Antarctic Division
Climate and Oceanography
The Southern Ocean is characterised by the Antarctic Circumpolar
Current (ACC), the world’s largest current, which flows
uninterrupted around Antarctica linking the Atlantic, Indian
and Pacific Oceans. The Drake Passage is the only chokepoint
in the flow of the ACC, where the passage and the bathymetry
of the Scotia Ridge restricts the flow and enhances mixing and
vertical circulation. The ACC comprises a number of distinct
fronts. The Sub-Antarctic Front (SAF) is the northern edge of
the ACC. Moving southward are the Polar Front (PF), Southern
ACC Front (SACCF) which lies close to the northern sea-ice limit,
and the Southern Boundary (SB) of the ACC. South of the SB is
the westward flowing Coastal Current and Antarctic Slope Front.
Each front is distinguished by distinct changes in oceanographic
characteristics in relation, temperature, salinity, density, and
oxygen concentration, each producing distinctive zones, each
characterised by discrete plankton assemblages (Hunt and Hosie,
2005). The ACC fronts often have a number of sub-branches.
There is a southward latitudinal decline in temperature from about
+8°C at the SAF to sub-zero temperatures in high latitudes. The
vertical water column is equally stratified through wind mixing,
horizontal circulation and the annual formation and melting of the
sea-ice.
Since the 1930s there has been a systematic and substantial
warming of the Southern Ocean with much of this concentrated
in the ACC (Aoki et al. 2003,). Surface temperatures have increased
by almost a degree, more than a tenth of a degree per decade, but
significant increases are recorded at all depths (Aoki et al. 2003,
Gille 2002). This warming can be attributed to the southward
movement of the ACC. Increased heat flux and subduction of
warmed surface waters are other potential causes of warming
waters, and may be due to human influence. The warming of the
Southern Ocean is not uniform. Ducklow et al. (2007) described
the western Antarctic Peninsula as “experiencing the most rapid
warming of any marine ecosystem on the planet”. At the same
Fig. 3. Continuous Plankton Recorder samples in the Southern
Ocean. Courtesy of Google Earth.
time as the warming and southward shift of the ACC, there has
been freshening of the upper surface waters of the Southern
Ocean. Freshening of the upper waters will lead to increased
stratification and potentially a reduction in the input of nutrients
into the euphotic zone.
Sea-Ice
The annual growth and retreat of Antarctic sea-ice is one of the
major drivers influencing the distribution, abundance and survival
of the biota of the region. At its maximum extent in September
sea-ice covers 19 to 20 million km2 before retreating to about 3
to 4 million km2 in February. The major concern is that global
warming will affect the extent and volume of sea-ice, which in
turn will affect the sea-ice organisms such as Antarctic krill. There
has been an approximate 25% loss of sea-ice between the 1950s
GACS/status
11
The Royal Society Report on Ocean Acidification (2005) has
predicted that increased absorption of CO2 will lead to an undersaturation of aragonite by the end of this century which would
result in plankton such as thecosome pteropod snails unable to
produce a shell. This could occur as early as 2050 (Orr et al. 2005).
Pteropods are very abundant in the Southern Ocean, they are
important in the diet of other zooplankton and myctophid fish,
and play an important role in the Southern Ocean carbon pump
removing carbon from the upper waters to the deep. We can only
speculate the consequences on the food web and carbon pump of
the loss of plankton with calcium carbonate shells.
Ecological Status
The Antarctic region can be split into three major regions. These
are the Atlantic sector of the Southern Ocean which includes the
Antarctic Peninsula, Weddell Sea, Scotia Arc and the southern
Atlantic. To the east is the Indian Ocean (eastern Antarctic)
sector extends from south of Africa to south of Tasmania. The
third region is the Pacific sector from south of New Zealand to
the Antarctic Peninsula incorporating the Ross, Amundsen and
Bellingshausen Seas. These sector correspond with FAO statistical
areas 48, 58 and 88, respectively. Each region will be treated
separately.
Atlantic sector
the total krill stock (Atkinson et al 2008) but density has declined
since the 1970’s (Atkinson et al. 2004). Sea-ice extent and Chl a
are shown to be key correlates and it has been suggested that
decreased ice extent will result in reduced recruitment. Salps
generally occupy the lower productivity regions of the Southern
Ocean and are more tolerant of warmer waters than krill and
have increased in the southern part of their range as krill have
decreased.
The south-west Atlantic is one of most productive sectors of
the ACC largely due to pronounced bathymetric variability.
Over much of the region spatial and temporal variability of
phytoplankton production is only beginning to be understood
(Whitehouse et al. 2012). Predictable phytoplankton blooms
are only found in a small sector of the south-west sector such
as the fringing island shelves and southern areas seeded by
iron from sources such as the Southern Scotia ridge. Elsewhere
ephemeral blooms occur stimulated by iron supplied from diverse
sources such as ice-melt, deep upwelling and periodic dust
deposits (Smith et al. 2007). Satellite imagery around the WAP has
demonstrated a decline of around 12% in summertime surface
Chl a over the last 30 years particularly north of 63°S although
substantial increases have occurred further south (Montes-Hugo
et al 2009).
Indian Ocean sector
Macro and mesozooplankton distributions within the Atlantic
sector have been reasonably well studied and species and
community distributions link closely to temperature and physical
features such as fronts and seasonal ice-cover (Whitehouse, 2012),
as well as large-scale atmospheric forcing . Although CPR research
in this sector is too recent to say anything regarding long-term
change the use of data from Discovery Investigations, samples
taken ~80 years ago prior to a rise in ocean temperatures of
~≥1°C , has hypothesised how macroplankton distributions may
have changed subsequently (Mackey et al 2012). Model results
showed that species generally showed a southward movement
in response to a 1°C rise in temperature, with some warmer water
species such as Themisto gaudichaudii and Euphausia triacantha
showing extensions of their historical range of up to 12° latitude
south. Conversely, cold water species showed contractions of their
ranges demonstrating how vulnerable these species might be to
further rises. Attempts to investigate changes in mesozooplankton
populations have, to date, been largely inconclusive. Vuorinen
et al. (1997) compared the spatial and temporal variation of
copepods in the Weddell Sea based on samples taken in 1929–
1939 and 1989–1993. Their comparison while finding no change in
overall abundance between periods, did detect recent increases in
the abundance of the copepod Calanus propinquus juveniles and
adults. However, other changes were only marginally significant
and they concluded that overall there were no uniform and
consistent changes that could be sensibly linked to environmental
change.
samples obtained post 1995. Again no significant differences in
distribution or community structure were apparent , although
more subtle changes were not ruled out. Changes in the
distribution of plankton resulting from atmospheric forcing
have been clearly demonstrated. At the WAP ENSO variability
invoked frontal movement of the Southern ACC Front resulting
in fluctuations between salp-dominated coastal zooplankton
assemblages and copepod-dominated oceanic zooplankton
assemblages. Takahashi et al. (2010b) reported the opportunity
to replicate one of Sir Alister Hardy’s early CPR transects across
Drake Passage and to compare species composition between
1927 and 2000. The two sets of tows recorded markedly different
species composition with Hardy’s tow recording high abundances
of larger copepods and chaetognaths, whereas the tow in 2000
recorded a dominance of smaller copepods, notably Oithona
similis, plus other species. Natural spatial and seasonal variation
cannot be discounted between the 1927 and 2000 tows, but it
does highlight the need for the establishment of routine CPR tows
in the region.
Discovery data obtained by Hardy and Gunther (1935) in 1926/7
from around South Georgia have also been compared with
Antarctic krill Euphausia superba and salps are major grazers in
the Southern Ocean. The south-west Atlantic contains ~70% of
Fig. 4. Continuous Plankton Recorder samples in the Southern
Ocean highlighting the three sectors used in the report
global/status
12
The SCAR Southern Ocean CPR Survey has conducted extensive
sampling in this region, notably south and west of Australia
since January 1991 (Hosie et al. 2003; McLeod et al. 2010).
Approximately, 36,000 samples at 5 nautical mile resolution
have been collected to date. In addition, the Japanese Antarctic
Research Expeditions (JARE) have conducted annual summer-time
routine Norpac net sampling on route to and from the Japanese
station Syowa since 1972. This builds on the extensive RMT net
sampling surveys conducted during three decades since 1981.
Zooplankton biomass (wet weight) from JARE Norpac sampling
1972/73 to 1995/96 in the Indian sector showed some cyclic
variation in abundance with 4-6 year periodicity, which may
be related to physical processes such as sea-ice extent or the
Antarctic Circumpolar Wave (Takahashi et al., 1998).
In the region off east Antarctica (90 to 160°E), meso-scale
variations in zooplankton communities have been observed due
to changes in ocean circulation patterns from 1987/88 to 1995/96
seasons (Chiba et al., 2001). The extensive spatial and temporal
coverage of the SO-CPR Survey has detected the close relationship
of zooplankton assemblages with the different frontal zones in
the Indian sector (Hunt & Hosie, 2005). There is also evidence
that these frontal zones have moved south. We expect that
zooplankton distribution ranges will move south with the fronts.
A sudden large increase in the abundance of foraminiferans has
been reported in the Indian sector collected in samples from
January 2005 (Takahashi et al., 2010a) and February to March
in 2002 . Takahashi et al. (2010a) suggested that the elevated
average Chl a concentration provided favourable conditions for
foraminiferans. Foraminiferans are a large group of protists; they
produce a shell made of calcium carbonate. Because calcium
carbonate is susceptible to dissolution in acidic conditions,
foraminiferans may be strongly affected by a changing climate
and ocean acidification. Moy et al. (2009) compared the shell
weights of the modern foraminiferan Globigerina bulloides
collected from sediment traps in the Southern Ocean with the
weights of foraminiferan shells preserved in the underlying
Sir Alister Hardy Foundation for Ocean Science
Holocene-aged sediments. They found that the modern shell
weights are 30–35% lower than those from the sediments,
consistent with reduced calcification induced by ocean
acidification. They noted that “it was unclear whether reduced
calcification will affect the survival of this and other species, but a
decline in the abundance of foraminifera caused by acidification
could affect both marine ecosystems and the oceanic uptake of
atmospheric carbon dioxide.”
Recently the red-tide forming, heterotrophic dinoflagellate
Noctiluca scintillans was observed in the sub-Antarctic Zone of
Southern Ocean up to 240 km south of Tasmania in December
2010 (McLeod et al., 2012a). This is the most southerly,
oceanic record of Noctiluca globally and can be linked to the
intensification of the East Australian Current (EAC), a situation
apparently caused by altered circulation patterns associated with
global warming. The prediction is the EAC is likely to continue to
strengthen and transport more warm water and eddies further
south. Thus may result in viable populations of Noctiluca become
established in the Southern Ocean in the future with unknown
effects for the food web.
The coccolithophorid Emiliania huxleyi is now very abundant, up
to 100 cells ml-1 between 2002 and 2006, in the sea-ice zone in
the eastern Antarctic region of 140°E whereas it was absent or
extremely rare south of 60°S prior to 1995 (Cubillos et al., 2007).
Similar extensions south have been observed along 45°E and may
be a function of general warming in the region.
Pacific sector
The region comprising the Ross, Amundsen and Bellingshausen
Seas has been the least studied of the Antarctic region. Most
of the focus of plankton research has focused on the Ross Sea,
whereas there has been no routine surveys of plankton in the
Amundsen or Bellingshausen Sea. Net sampling studies have
been conducted, some recording extremely high abundances
of pteropods, of up to 1397 individuals m-3 or 63% of total
zooplankton numbers (Pane et al., 2004). Limacina helicina
antarctica was most likely the main contributor to these numbers
and is a species likely to be affected by ocean acidification.
Routine CPR tows are now conducted by New Zealand in support
of the SO-CPR Survey since 2006. Results to date show a high
degree of spatial and seasonal variation in abundance. This is
reflected in predictive biogeographic models using Boosted
Regression Tree modelling (Pinkerton et al., 2010), which has
predicted high numbers of the cyclopoid copepod Oithona similis
in the mid-ocean, Permanent Open Ocean and Polar Frontal
zones, and very low abundances in the southern Amundsen
and Bellingshausen Seas. These low abundances have since
been confirmed by CPR tows by Russia in 2008. The predictive
models have also identified a number of persistent hot spots of
high abundance in the eastern Antarctic and south-east of New
Zealand (Pinkerton et al., 2010).
The Northeast Pacific: the
temperate shelf region and the
oceanic subarctic gyre
Sonia Batten
North Pacific CPR Survey Coordinantor
Climate and Oceanography
The North Pacific CPR survey consists of two transects, both
originating in the Strait of Juan de Fuca that forms the border
between Washington State, USA and British Columbia, Canada.
The north-south CPR transect crosses the eastern NE Pacific
terminating in Cook Inlet, Alaska (6 times per year, monthly
between about March and September). This transect began
sampling in 2004 but from 2000 to 2003 a similar transect
between Prince William Sound, Alaska and California was sampled.
The east-west transect follows a great circle route across the
Alaska Gyre, Aleutian Island chain, southern Bering Sea and
western Pacific gyre to the coast of Japan (3 times per year, about
April, June and September). Sampling began here in 2000.
The status of two eco-regions are described here; the oceanic
subarctic gyre (equivalent to the eastern portion of Longhurst’s
biogeochemical province PSAE) and the temperate shelf and slope
to the east, (equivalent to the northernmost part of Longhurst
province CCAL). Note that the ALSK coastal province is also
sampled by the CPR transects but at 3 widely separated points and
with less temporal resolution than the two regions described here.
Future reports may include this region. More detailed information
on the status of regions of the North Pacific from a wide range of
data sources can be found in McKinnel and Dagg (2010).
Unlike much of the global ocean the NE Pacific has been
experiencing colder than average SST since 2008, primarily due to
La Niña conditions which have predominated into spring 2012. For
this report data from the most recent cool phase (2008 to 2011)
have been compared to the 2000-2007 data which comprised
GACS/status
13
Fig. 5. Continuous Plankton Recorder samples in the Northeast
Pacific. Courtesy of Google Earth.
some cool and some very warm years. Four summary indices are
considered, mesozooplankton biomass (estimated by summing
the product of taxon specific dry weight and taxon abundance),
mean Copepod Community Size (as described in Richardson
et al., 2006), Phytoplankton Colour Index (see e.g. Batten et al.,
2003 for a definition) and the proportion of the total diatom and
dinoflagellate cell counts that were diatoms.
Ecological Status
Oceanic region
The NE Pacific gyre region is a high nitrate low chlorophyll (HNLC)
region, and as such it has little seasonal variation in chlorophyll
levels and is dominated by small cells (Harrison et al., 1999). The
annual mean PCI bears this out with March having the lowest
values, rising slightly into spring and summer and then higher
into autumn. The monthly mean ranges only from 0.5 to 1.04.
The mean monthly PCI values for the most recent 2008-2010 cool
period were lower than the 2000-2007 monthly means.
The large phytoplankton cells that are identified from CPR
undergo an ontogenetic migration to depth in summer. Copepod community size shows a shift
from a mean of 3.8-4.2 between March and July to 2.2-25 during August-October. Biomass reaches a
peak in late spring/early summer. In the recent 2008-2011 cool period the biomass peak was delayed
by about a month into summer. The copepod community had a larger mean size in March in early
spring of the years 2008-2011, possibly caused by an absence of smaller taxa. The method used to
determine copepod community size ignores the separate copepodite stages which have been used
elsewhere to show a change in phenology associated with cold and warm conditions in the NE Pacific
and which would have been more abundant in March than the larger copepodite stages. Batten and
Mackas (2009) showed that there has been a narrower cohort of the dominant Neocalanus plumchrus
copepods in recent years. While copepod community composition is not discussed in this report it
should be noted that warm water species were absent, or in low numbers, during the cool period and
not found as far north (Batten and Walne, 2011).
Coastal region
Although termed the coastal region, because the shelf is relatively narrow and the CPRs are not
deployed until clear of coastal traffic, the majority of the CPR samples are over deeper waters on the
slope. However, they are outside of the main gyre, in areas where mesoscale eddies and upwelling
may affect productivity. PCI is higher in each month than in the oceanic region, although there is
no real evidence of a spring bloom with levels consistent through the year at 0.7-1.6. During the
recent 2008-2011 period spring values were higher than autumn values, in contrast to the 2000-2007
period, driven mainly by high values in April 2009 although 2011 also had higher spring values than
late summer. Otherwise, values for this period were similar to those for 2000-2007. The contribution
of diatoms shows a similar pattern to the oceanic area, being high through spring and summer and
lower in the autumn when dinoflagellates occur in higher numbers. The recent 2008-2011 period had
similar numbers, with evidence that dinoflagellates were also lower in numbers in the autumn.
The copepod community has a mean size smaller than the oceanic region through spring and
summer, ranging from 1.8 to 3.4. The subarctic species are still present, producing a larger mean size
in the spring, but smaller shelf species are also numerous reducing the overall mean size until the
autumn when the oceanic and coastal communities have almost identical size. The biomass peak
is typically earlier than in the oceanic region, and the cool 2008-2011 period did not show a delay
in the peak timing as the oceanic region did, if anything it was earlier. However, the mean copepod
community size was noticeably smaller in the 2008-2011 period, likely caused by unusually high
numbers of Pseudocalanus in 2009 and 2010.
Fig. 6. Mean monthly values of each index for the coastal region (left) and the oceanic
region (right). Black lines include data from 2000 to 2007 while coloured lines comprise
data from 2008 to 2011.
In summary, the impact of the recent cool period is clearly evident in the plankton; a later spring
zooplankton peak in oceanic waters. There was a noticeable reduction in the abundance of
dinoflagellates across both regions and a decline in PCI values in the oceanic region. However, by
April 2012 the La Niña conditions were becoming neutral so future updates may reveal additional
changes in lower trophic level phenology and community composition.
samples are not likely to be representative of the phytoplankton community here, however, of those
cells counted diatoms typically comprise 96-98 % in spring and summer, falling to 85-88% in autumn
when dinoflagellates become more abundant. During the 2008-2011 period, diatoms comprised a
greater proportion (92-100% in all months) suggesting a decline in dinoflagellates during the cool
period.
The oceanic mesozooplankton is dominated in the spring by large calanoid copepods that typically
global/status
14
Sir Alister Hardy Foundation for Ocean Science
The Northwest Pacific: Oyashio
region and western North
Pacific subarctic gyre
The Benguela Current Large
Marine Ecosystem (BCLME)
Sanae Chiba
Hans M. Verheye
Research Institute for Global Change, JAMSTEC, 3173-25
Showamachi, Kanazawaku, Yokohama, 2360001, Japan
Department of Environmental Affairs: Oceans and Coasts Research
P.O. Box 52126, Victoria & Alfred Waterfront, Cape Town 8000,
South Africa
The Japanese Team is participating in the North Pacific CPR survey
by analyzing samples collected in the area west of 170°E on the
east-west transect, which has been conducted 3 times per year
since 2000 (see the Northeast Pacific Status details of the North
Pacific CPR survey). Prior to the analysis, the area was subdivided
at the meridional boundary of 155°E according to biogeochemical
properties, into Oyashio region (west section) and western North
Pacific subarctic gyre (east section).
Climate and oceanography
Ecological Status
Oyashio region
The Oyashio region is known to have a distinctive spring bloom in
April – May with rich macronutrient supply by wintertime water
mixing and high spring-summer zooplankton abundance. Bloom
species are dominated by centric diatoms and large calanoid
copepods, including three Neocalanus spp. and Eucalanus bungii,
which perform ontogenetic vertical migration.
Influence of Aleutian Low (AL) dynamics, which is the climatic
forcing of the Pacific Decadal Oscillation (PDO), on interannual
and interdecadal variations in water temperature is obvious,
with cool (warm) anomaly in the years of strong (weak) AL and
positive (negative) PDO. That cool-warm cycle determines the
lower trophic level phenology. Retrospective analysis based on
the Odate Collection data sets showed that abundance peak of
Neocalanus plumchrus delayed approximately one month during
the cold period with positive PDO for the mid 1970s – late 1980s
compared to the warm period in the1990s (Chiba et al., 2006). In
recent years, satellite observation and CPR survey revealed that
the spring bloom occurred later in cool years, 2003-2007, and
earlier in warm years, 2000-2002 and 2008, 2009.
Relative abundance of dinoflagellates to diatoms significantly
increased in the years of rapid summertime warming, rather
than merely being correlated to monthly or seasonal mean
temperature, indicating seasonal process in mixed layer
Fig. 7. Continuous Plankton Recorder samples in the Northwest
Pacific. Courtesy of Google Earth.
stratification might be responsible for formation of seasonal
phytoplankton community structure (Chiba et al., 2012).
Western North Pacific subarctic gyre
Dominant bloom species in this area are similar to those of
Oyashio region, centric diatoms and large calanoid copepods. This
area is generally characterized as HNLC region in particular inner
part of the gyre. However, as extensive phytoplankton bloom
occurs along the coast of Kamchatka peninsula and occasionally
expends to offshore region, CPR transects potentially run over
areas with large spatial-temporal heterogeneity in terms of
environmental and biological properties.
Relationship between the PDO index and water temperature
anomaly is seasonally reversed; these are positively correlated
from winter to spring, and negatively correlated from spring to
summer, indicating colder (warmer) winter tends to be followed
by hot (cooler) summer. This unique temperature seasonality
is considered to largely influence plankton phenology and
community structure in this area.
GACS/status
15
The Benguela Current is the eastern limb of the South Atlantic
sub-tropical gyre and includes the Benguela Current Large Marine
Ecosystem (BCLME). The BCLME stretches along the coasts of
Angola, Namibia and South Africa, from 5°S-12°E off Cabinda in
Angola to the Nelson Mandela Metropole (Port Elizabeth) on the
south coast of South Africa at 34°S-26°E. Unlike the other three
major eastern boundary current systems, the Benguela upwelling
system is uniquely bounded and significantly influenced by warmwater regimes of equatorial Atlantic and Indian Ocean origin at its
northern and southern ends. The Benguela region is also strongly
influenced by the Southern Ocean because of its close proximity.
Moreover, the region is situated at the choke point in the “global
ocean climate conveyor belt”, where warm surface waters from the
Indo-Pacific pass around Africa into the Atlantic.
Not surprisingly, this complex ecosystem is characterized by
considerable environmental variability on several temporal
and spatial scales. Features of its circulation inherent of other
upwelling systems include: offshore Ekman-transport at the
surface driven by equatorward winds; a poleward undercurrent
along the continental shelf-break; and the growth and decay
of frontal jets into meanders, eddies and filaments. The South
Atlantic high-pressure system and its seasonal shift facilitate
the upwelling-favourable, equatorward wind regime, which is
dominant during summer in the southern Benguela and perennial
in the northern Benguela. Based on this and associated physical
and biological characteristics, the BCLME is divided by the Lüderitz
Upwelling Cell and Orange River Cone (LUCORC) area (at around
25°S) into the northern (= the Namib ecoregion) and southern (=
the Namaqua ecoregion) Benguela upwelling regimes.
Besides being complex and highly variable, the Benguela is a
highly productive ecosystem, characterised by phytoplankton-rich
coastal waters. Phytoplankton variability is driven by the nonlinear relationships between upwelling-favourable winds that lift
nutrient-rich water to the surface, solar radiation, stabilization,
sinking and the response times of individual species. Species
of zooplankton provide a link between primary producers
and larger heterotrophs, which tend to prey on them in a sizeselective manner. These preferences suggest the importance of
zooplankton distributions to the composition and distribution of
planktivorous (mainly pelagic) fish resources.
The Benguela upwelling system supports a host of commercially
valuable living marine resources including small pelagic, midwater and demersal fish species, as well as rock lobster. Diets of
many top-predators, which include large pelagic fish, seabirds
and marine mammals, in turn depend on the availability of these
economically important fish stocks, which they favour as prey.
Dietary analyses therefore provide useful indicators of the state
of these stocks, thereby also tracking shifts in species dominance.
The abundances of harvested fish stocks not only depend on the
variability of the physical environment and its influence on food
availability, but also on fishing. Indeed, human impact, which
includes pollution, mining, exploration for and extraction of oil
and gas in addition to fisheries, is superimposed onto the inherent
natural variability of the ecosystem.
Ecological Status
The following paragraphs provide a summary of recent
observations of ecological conditions prevailing primarily off the
west coast of South Africa, i.e. the southern Benguela. Data were
obtained from a variety of sources including web-based sources,
satellite sensors, coastal and moored instruments, and research
and routine monitoring cruises. In September 2011, the first CPR
survey was launched between Luanda, Angola and Durban, South
Africa and samples from this inaugural and subsequent tows in
the Benguela Current are currently being analysed at SAHFOS
in Plymouth, UK and the local CPR Centre in Cape Town. A good
correlation exists between warm (El Niño) and cold (La Niña)
events in the equatorial Pacific and, respectively, positive and
negative sea level atmospheric pressure anomalies along the
South African west coast. The relationship persisted through the
past 2010/2011 austral summer when Pacific La Niña conditions
were associated with below-average atmospheric pressures along
the west coast. At Hondeklip Bay, in particular, the pressure was
very low - in fact the lowest in the available data series since 1981.
The St Helena Island climate index (HIX), of which the winter
(July-September) value is thought to be indicative of upwelling
in the northern Benguela Current region, had been positive since
the winter of 2006 – indicating above-average upwelling. The
index level has, however, been declining since 2006 and became
slightly negative during winter of 2011. During the 2010/2011
summer both the southerly and easterly wind components
measured at Cape Point increased to levels which, in January 2011,
were respectively about twice and three times stronger than the
previous maxima seen in this 1960 to 2011 series. Above- average
southerly and easterly winds are in agreement with what was
expected from the La Niña conditions, which prevailed in the
tropical Pacific during the summer.
Examination of the January 1850 to December 2010 Cape Town
precipitation series in conjunction with sea surface temperature
(SST) anomalies and wind in the Southern Ocean indicates
intensification and a poleward shift of the west wind belt which,
according to modelling, should result in more Agulhas Current
water leaking into the South-East Atlantic, increasing the
incidence of positive SST anomalies and thus, possibly, enhancing
the risk of abnormal precipitation events.
The 2002-2011 time-series of MODIS satellite-derived SSTs indicate
that along the entire west coast shelf north of Cape Point, SSTs
were far above average during the 2009/2010 summer (except for
January 2010). The positive anomaly persisted in the 2010/2011
summer but much less severely so. In both summers the anomaly
weakened from north to south. These conditions agree well
with weak southerly winds and upwelling indices observed in
scatterometer data. During the 2010 and 2011 winters west coast
SSTs were cooler than normal and this also agrees well with wind
and upwelling indices. On the western Agulhas Bank SSTs were
above average during the 2009/2010 summer and 1-1.5°C below
average in 2010/2011. The cool 2010/2011 conditions are in
agreement with very strong easterly and southerly winds recorded
at Cape Point. The 1856-2010 Kaplan 5°x5° global SST anomaly
data set was used to compute the annual SST anomalies for the
30-35°S, 15-20°E block along the South African west coast. The
resulting series showed that SSTs in the South East Atlantic have
been increasing from around the 1970s at a mean rate of about
0.06°C per decade.
Time series of Ekman upwelling indices computed from 1999 2011 satellite scatterometer wind data for Hondeklip Bay, Cape
Columbine, and Cape Point indicate the following inter-annual
trends and features: (1) The winter indices at all three sites
demonstrate positive trends (i.e. towards increasing levels of
upwelling) from 2007 to 2011. This is in agreement with observed
decreasing trends in winter northerly and westerly winds over this
period; (2) In 2011 upwelling was perennial at all three sites. This is
a common occurrence at Hondeklip Bay and Cape Columbine but
global/status
16
Fig. 8. Continuous Plankton Recorder samples in the South
Atlantic. Courtesy of Google Earth.
this was the first time it was also observed at Cape Point and was
expected from the strong southerly and easterly winds observed
at this location during the 2010/2011 summer and 2011 winter;
(3) During the past two summers upwelling at Hondeklip Bay and
Cape Columbine was at the lowest level yet seen in the series;
(4) At Cape Point upwelling was more or less at the average level
during the 2009/2010 summer but at a series maximum in the
2010/2011 summer. Coastal nutrient concentrations on the St.
Helena Bay Monitoring line (SHBML, 2000-present) were generally
high from the beginning of the series in 2004 to 2006/2007
and this was followed by about two years of strikingly low
concentrations (up to 2009). Thereafter concentrations increased
again to reach high concentrations during the 2010/2011 summer.
These high nutrient concentrations are contrary to what is
expected from the above average sea surface temperatures and
low levels of upwelling recorded at Cape Columbine and vicinity
during the 2010/2011 summer.
In the SHBML time-series of dissolved oxygen concentration at
the bottom, the years 2006-2008 stand out as a period when low
oxygen concentrations extended unusually far offshore. This was
a period of anomalously low surface temperatures, relatively high
Sir Alister Hardy Foundation for Ocean Science
vicinity of Cape Columbine had been relatively low during the
2009/2010 summer, but shows that in March 2010 moderately
high concentrations (5 to10 mg.m-3) extended more than 170 km
from the coast - the farthest yet seen in the 2000-2011 series. The
time-series further confirms the high nearshore concentrations of
the early 2010/2011 summer seen further along the west coast,
as well as the low concentrations of the late summer and average
concentrations of the 2011 winter.
A time-series of autumn abundances of copepod species collected
in St Helena Bay since 1951 shows an initial gradually increasing
trend in copepod abundance that however reversed in the
mid-1990s and steadily declined to the mid-2000s, reversing and
increasing again from thereon. This pattern, although observed
in all dominant species albeit to varying extents, is largely driven
by the abundances of the small calanoid and cyclopoid species.
Whereas the copepod community of the 1950s and 1960s was
generally dominated by larger species, indicative of cooler ocean
conditions, smaller species predominated during the 1990s and
2000s, indicative of ocean warming.
levels of upwelling and high chlorophyll concentrations in the
St. Helena Bay area. At the GWB002 monitoring station bottom
oxygen concentrations were very low in late winter/spring of
2011 and this coincided with above-average southerly winds and
upwelling during the 2011 winter.
The 2002-2011 time-series of surface ocean colour obtained
from MODIS satellite images indicate below-average surface
chlorophyll concentrations along the west coast during the
2009/2010 summer, except for the Cape Columbine-Cape Point
region where it was slightly above average. This is in agreement
with observed high SSTs and weak upwelling. By contrast, Chl
concentrations were far above average along the entire west
coast north of Cape Point during the 2010 winter, which would
be expected from an observed declining trend in winter northerly
and westerly winds, below-average SSTs and above-average
upwelling. Surface Chl concentrations during the 2010/2011
summer were spatially variable along the west coast, ranging
from very low in the north to above average in the south. This
pattern fits in well with southerly winds and upwelling, which
also increased from north to south. Concentrations along the
west coast during the 2011 winter were near average and this
is contrary to what was expected from the observed increasing
trend in winter upwelling.
The SHBML time-series of monthly in situ measured surface
chlorophyll concentrations confirms that concentrations in the
Bi-annual sampling of zooplankton on the western Agulhas Bank
(WAB) and central Agulhas Bank (CAB) has taken place each year
during spring (October-November) from 1988 onward. Mean
biomass on the WAB has declined by 36% from the first half of the
time-series (1988-1999) to the second half (2000-2010). Biomass
was relatively high over the periods 1988-1990, 1996-1999 and
2002-2004, but was relatively low from 1991-1993, 2000-2001,
and 2005-2010. It was particularly low in 2005 and 2007, but has
increased gradually since then. Both the biomass and proportion
of Calanus agulhensis, the dominant large copepod on the
Agulhas Bank, declined over the time-series. Most other copepod
species also declined over the time-series, but to a far lesser extent
than C. agulhensis. On the CAB there was a more marked decline
- with less interannual variability - of total copepod biomass as
well as that of Calanus agulhensis than on the WAB. Mean copepod
biomass on the CAB, averaged over the time-series, is almost
identical to that of the WAB, but has declined by 59% from the first
half of the time-series (1988-1999) to the second half (2000-2010),
while mean biomass of C. agulhensis has declined by as much as
68%. Moreover, there has been, between 1988 and 2008/2009,
a shift from a large-species-dominated copepod community to
an increasingly smaller copepod-dominated community on the
Agulhas Bank. This is suggestive of progressive warming in the
region and may reflect the slow but steady warming trend for
the Agulhas Current Large Marine Ecosystem reported in the
literature.
GACS/status
17
Fig. 9. Continuous Plankton Recorder samples in the Northwest
Atlantic. Courtesy of Google Earth.
Monitoring transport of spawning products (eggs and early
larvae) of pelagic fish from their spawning grounds on the WAB
to the west coast nursery area was initiated in August 1995 and
has since been performed more or less monthly up to the present
along the SARP (Sardine and Anchovy Recruitment Programme)
Monitoring Line. The SARP line extends southwestwards from the
Cape Peninsula through the equatorward flowing shelf-edge jet
current along the west coast of South Africa. The results indicate
relatively low annual abundances of anchovy eggs and larvae
from the 1995/1996 to 1999/2000 seasons and generally higher
abundances from 2001/2002 onwards. The abundance of anchovy
eggs along the SARP line from 1995 to 2010 was found to be
significantly negatively correlated with the biomass of Calanus
agulhensis on the WAB during late spring/early summer, the
peak spawning period of anchovy. This observation supports the
hypothesis that low copepod biomass on the WAB and CAB during
spring/summer is a consequence of predation by a large anchovy
biomass during the time of their peak spawning, presumably
accompanied by a high abundance of eggs. The low abundance
of sardine eggs and larvae since 2001 corresponds to an eastward
shift in the distribution of adult sardine along the South Coast.
Sardine larvae spawned east of Cape Agulhas are likely to be too
Canadian Atlantic Zone Monitoring Programme:
Scotian Shelf, Newfoundland Shelf and Labrador
Basin ecoregions.
Erica Head
Fisheries and Oceans Canada, Ocean and Ecosystem Sciences Division, Bedford Institute of
Oceanography, P.O. Box 1006, Dartmouth, NS, B2Y 4A2, Canada
Climate and oceanography
Fig. 10. Annual average abundances by decade of selected phytoplankton and zooplankton
taxa on the Western Scotian Shelf (WSS) and the South Newfoundland Shelf (SNL) and in the
region of the sub-polar gyre between 40 and 45 degrees west (40-45oW) for the decades
since the 1960s and for 2010.
large, by the time they reach the SARP line, for capture with the mini-Bongo net used for sampling on
the line.
The diet of Cape gannets has been monitored at a number of locations along the West Coast on
a monthly basis since 1978. On average, anchovy contributed 20-40% of the diet over the period
1978−2010. The contribution of sardine to the diet increased in the 1980s, as South Africa’s sardine
abundance increased. Sardine remained important in the diet until the early 2000s. Up until 2003, the
combined contribution of anchovy and sardine to the diet averaged 50-75%, but fell dramatically in
2004 with a minimum of 13% in 2005. During 2009 and 2010 the sardine contribution increased to
the highest level since 2003 but the anchovy contribution dropped. Interestingly, the contribution of
horse mackerel to the gannet diet increased during 2010 to the highest level in the data series.
global/status
Continuous Plankton Recorders (CPRs) have been towed along routes between Iceland and
Newfoundland (the Z route) and between Newfoundland and the NE coast of the United States (the E
route) since the early 1960s. In 2010 the North Atlantic Oscillation (NAO) index dropped to its lowest
level since 1969. When this index of atmospheric conditions is low, air and water temperatures in
the Labrador Sea region are relatively warm and winter-time convective vertical mixing is relatively
shallow.
Ecological status
For the shelf regions, the phytoplankton colour index (PCI) and diatom abundance remained at the
high levels of the 1990s and 2000s in 2010, while dinoflagellate abundance returned to the low levels
of the 1960s and 1970s on the western Scotian Shelf, but remained at the high levels of the 1990s and
2000s on the eastern Scotian Shelf and the South Newfoundland Shelf. The regions in the Labrador
Basin ecoregion showed similar patterns of change for all three phytoplankton indices, with gradual
increases after low values the 1980s, which were sustained in 2010. The abundance of young Calanus
(Calanus I-IV) and the late stage of Calanus finmarchicus (C. finmarchicus V-VI) has remained relatively
stable over the decades on the Scotian Shelf and in the Labrador Basin (40-45oW). Three taxa,
Coccolithophores, Foraminifera and Pteropods, are used to monitor potential effects of increasing
acidification in the NW Atlantic. The abundances of Coccolithophores have increased in all regions,
while abundances of foraminifera have either decreased (Scotian Shelf ), or increased (Labrador
Basin). Pteropods, which have been counted for all decades, had their highest levels in the 90s in
shelf regions, while in the sub-polar gyre levels have slightly increased over the decades.
18
Sir Alister Hardy Foundation for Ocean Science
The Australian Continuous Plankton Recorder
Survey (AusCPR)
Anthony J. Richardson and Graham Hosie
University of Queensland and CSIRO Marine and Atmospheric Research, Australia, Australian Antarctic
Division, Australia
Ecological Status
The AusCPR survey runs tows in Australian waters, across to New Zealand and in the Southern
Ocean (in conjunction with SO-CPR). Since 2009, we have towed >35,000 nautical miles, counted
a total of 3,379 samples for 637 zooplankton taxa and 224 phytoplankton taxa. This is a relatively
new survey and we are just starting to analyse the data collected. Australia is unique globally in
being bounded by two poleward-flowing warm-water currents. We sample the east, west and
south coasts of Australia, with our best sampled region on the east coast. This is the East Australia
Current, a warm, southward current. Generally waters around Australia are warm and so many of
the copepods are small. Our mean copepod size across all samples is 1.15 mm. Despite the small
copepod size, there is still the a strong diel vertical migration signal, with the abundance doubling
in the middle of the night. Seasonally off the east coast, diatoms peak in Aug/Sep, dinoflagellates
Dec-Mar, and copepods in Apr/May and Nov/Dec. Interannually, there were significantly more
diatoms, dinoflagellates, and copepods in 2010 than in 2009 or 2011. Regionally, the ratio of
diatom to diatoms+dinoflagellates declines on the east coast from north to south, from 85-92% in
the north to 60% in the south. This is because of the steep decline in diatoms and dinoflagellates
remain reasonably consistent.
Fig. 11. Continuous Plankton Recorder samples in Australian
waters. Courtesy of Google Earth.
The AusCPR survey has already highlighted the benefit of long-term observations to providing
context for ephemeral events. During the 3 days following 22 Sept 2009, after a severe 10-year
drought, a massive dust plume originating in Central Australia swept eastward and covered
an area 25 times the size of England. Some 16 Tg of dust was stripped from central Australia
with 75,000 t/h estimated to have crossed the New South Wales coast. In the wake of this dust
event, we discovered massive concentrations of 4-5 μm diameter black spinose fungal spores
in coastal samples collected between Brisbane and Sydney from 16-20 Oct 2009 (up to 150,000
spores per m3). The formalin-preserved plankton recorder silks, appeared black as if they were
covered in oil. Using molecular sequencing of 3 different genes, we unambiguously identified
this fungus as Aspergillus sydowii (99-100% sequence match). We also succeeded in establishing
viable sporulating cultures, even from formalin preserved material and from samples kept at
-20°C for several months. This fungus was never seen before Oct 2009 and has not been since.
Interestingly, there has not been a similar event reported by the North Atlantic CPR survey over
the past 70 yrs, the Southern Ocean survey over the past 20 yrs or the North Pacific survey over the
past decade. A. sydowii is believed to essentially be a terrestrial fungus, but salt-tolerant and well
capable of growing in the sea. We speculate that A. sydowii spores originated from terrestrial Lake
Eyre habitats, were deposited in the form of nutrient-rich floating dust slicks in Australian coastal
waters, which allowed rapid fungal growth and sporulation. In laboratory simulations sporulation
only occurred at the air-water interface. Aerosol fungal impacts have been well-documented in
terms of human health, agriculture, ice nucleation, cloud formation and atmospheric chemistry,
but broader impacts on marine ecosystems remain largely uncharted.
GACS/status
19
Basin-scale and ecoregional assessment of
the North Atlantic
global/status
20
Sir Alister Hardy Foundation for Ocean Science
Ecoregional assessment of the North Atlantic
(a)
Sampling by the Continuous Plankton Recorder
The Continuous Plankton Recorder survey is a long-term sub-surface marine plankton
monitoring programme consisting of a network of CPR transects towed monthly
across the major geographical regions of the North Atlantic. It has been operating
in the North Sea since 1931 with some standard routes existing with a virtually
unbroken monthly coverage back to 1946. After each tow, CPR samples are returned
to the laboratory for routine analysis including the estimation of phytoplankton
biomass (Phytoplankton Colour Index), and the identification of over 500 different
phytoplankton and zooplankton taxa (Warner and Hays 1994). Direct comparisons
between the phytoplankton colour index and other chlorophyll a estimates including
SeaWiFS satellite estimates indicate strong positive correlations (Batten, et al 2003;
Raitsos,et al. 2005) . The CPR instrument is towed at the surface behind volunteeroperated vessels (ships of opportunity), sampling plankton onto a moving 270 µm
band of net silk as the vessel and CPR unit traverse the North Atlantic and/or North
Sea. Within the CPR instrument, the net silk and its captured plankton are preserved
in formalin until they are returned to SAHFOS. During the processing, the net silk is
divided into sections representing 10 nautical miles of towing, and each section is
analysed for plankton composition and abundance. Using this analysis method, 500
plankton taxa have been routinely identified and counted by the CPR survey since
1958.
Due to the mesh size of CPR silks, many phytoplankton species are only semiquantitatively sampled owing to the small size of the organisms. There is thus a
bias towards recording larger armoured flagellates and chain-forming diatoms
and that smaller species abundance estimates from cell counts will probably be
underestimated in relation to other water sampling methods. However, the proportion
of the population that is retained by the CPR silk reflects the major changes in
abundance, distribution and specific composition (i.e. the percentage retention is
roughly constant within each species even with very small-celled species) (Edwards,
et al 2006). The CPR now has a water sampler housed onboard certain CPRs to provide
additional data and sample the whole size-spectrum of plankton using molecular
techniques from bacteria and viruses to flagellates and other taxa not normally
identified using standard CPR analysis. For the purpose of this assessment, the North
Atlantic Basin has been geographically subdivided into different ecoregions. The
40 geographical regions shown in the figures are known as the CPR standard areas.
Included in this assessment are some trends in the microzooplankton community
and trends in marine pathogens from molecular analysis of the CPR sample archive.
The figures 13-15 showing regional trends in standard areas were generated using
standard statistical methods for calculating annual means.
(b)
Fig. 12. (a) Continuous Plankton Recorder survey standard areas used in the analysis of regional patterns of
plankton for the North Atlantic. (b) Monthly and annual sampling effort for the standard areas from 1958-2011.
GACS/status
21
Basin scale trends in plankton and natural variability
To summarise the long-term trends in phytoplankton in the North
Atlantic Basin we used indices of plankton that included the CPR
Phytoplankton Colour Index (PCI) and the sum of the abundance
of all counted diatoms and all counted dinoflagellates and total
copepod numbers and mean copepod size. Using bulk indices like
this are less sensitive to environmental change and will quite often
mask the subtleties that individual species will give you; however,
it is thought that these bulk indices represent the general
functional response of plankton to the changing environment. In
the North Atlantic, at the ocean basin scale and over multidecadal
periods, changes in plankton species and communities have been
associated with Northern Hemisphere Temperature (NHT) trends,
the Atlantic Multidecadal Oscillation (AMO), the East Atlantic
Pattern (EAP) and variations in the North Atlantic Oscillation (NAO)
index. These have included changes in species distributions and
abundance, the occurrence of sub-tropical species in temperate
waters, changes in overall plankton biomass and seasonal
length, changes in the ecosystem functioning and productivity
of the North Atlantic (Beaugrand, et al 2003; Edwards, et al 2001;
Edwards, et al, 2002; Reid & Edwards, 2001; Edwards & Richardson,
2004).
While contemporary observations over a 10 year period of
satellite-in situ blended ocean chlorophyll records indicate that
global ocean net primary production has declined over the last
decade particularly in the oligotrophic gyres of the world’s oceans
(Behenfeld, et al 2006). Over the whole temperate NE Atlantic
there has been an increase in phytoplankton biomass with
increasing temperatures but a decrease in phytoplankton biomass
in warmer regions to the south (Richardson & Schoeman, 2004), as
shown in Figs 13 and 14, respectively. Presumably this is a tradeoff between increased phytoplankton metabolic rates caused by
temperature in cooler regions but a decrease in nutrient supply in
warmer regions.
The amount of nutrients available in surface waters directly
dictates phytoplankton growth and is the key determinant of
the plankton size, community and foodweb structure. In terms
of nutrient availability, warming of the surface layers increases
water column stability, enhancing stratification and requiring
more energy to mix deep, nutrient-rich waters into surface layers.
Particularly warm winters will also limit the degree of deep
convective mixing and thereby limit nutrient replenishment
necessary for the following spring phytoplankton bloom.
It must be noted, however, that climate variability has a spatially
heterogeneous impact on plankton in the North Atlantic and
not all regional areas are correlated to the same climatic index.
For example, trends in the AMO are particularly prevalent in the
oceanic regions and in the sub-polar gyre of the North Atlantic
and the NAO has a higher impact in the southern North Sea where
the atmosphere-ocean interface is most pronounced. This is also
apparent with respect to the Northern Hemisphere Temperature
where the response is also spatially heterogeneous with areas of
the North East Atlantic and shelf areas of the North West Atlantic
warming faster than the North Atlantic average and some areas
like the sub-polar gyre actually cooling. Similarly, regime shifts or
abrupt ecosystem shifts do not always occur in the same region or
at the same time. The major regime shift that occurred in plankton
in the late 1980s was particularly prevalent in the North Sea and
was not seen in oceanic regions of the North Atlantic. However, a
similar regime shift occurred in the plankton colour 10 years later
in the Icelandic Basin and in oceanic regions west of the British
Isles. The different timing and differing regional responses to
regime shifts have been associated with the movement of the
10oC thermal boundary as it moves north in the North Atlantic
(Beaugrand, et al. 2008).
In examining the long-term trends in the plankton indices the
general pattern is an increase in PCI for most regions in the North
Atlantic with differing timings for the main step-wise increase
being later in oceanic regions compared to the North Sea. For the
dinoflagellates there has been a general increase in abundance
in the North West Atlantic and a decline in the North East Atlantic
over a multi-decadal period (see Fig. 14). In particular, some
regions of the North Sea have experienced a sharp decline over
the last decade. This decline has been mainly caused by the
dramatically reduced abundance of the Ceratium genus in the
North Sea. However, Ceratium abundance has recovered in the
North Sea over the last two years. For the diatoms there is not
really a predominant trend for the North Atlantic Basin (Fig. 14)
as a whole but some regions show a strong cyclic behaviour over
the multidecadal period. The time signal resembles an oscillation
of about 50-60 years and a minimum around 1980 reflecting
changes in the AMO signal. Trends in copepod abundances have
been more stable in oceanic regions but have shown a decrease in
abundance particularly in the southern North Sea.
diatoms.
Indirectly the progressive freshening of the Labrador Sea region,
attributed to climate warming and the increase in freshwater
input to the ocean from melting ice, has resulted in the increasing
abundance, blooms and shifts in seasonal cycles of dinoflagellates
due to the increased stability of the water-column (Johns, et
al. 2001). Similarly, increases in coccolithophore blooms in the
Barents Sea and HABs in the North Sea are associated with
negative salinity anomalies and warmer temperatures leading
to increased stratification (Edwards, et al, 2006; Smyth, et al,
2004). It seems likely that an important environmental impact
caused by climate change is an increase in the presence of haline
stratification in regions susceptible to fresh-water inputs resulting
in an increase in bloom formation.
In summary, while climate warming is a major driver for the
overall biomass of phytoplankton, diatoms are less influenced by
temperature and show a strong correlation with the AMO signal
and wind intensity in many regions. The increase in diatoms
associated with the positive phase of the AMO and the decline in
dinoflagellate abundance over the last 10 years in the NE Atlantic
can be reflected in the diatom/dinoflagellates ratio favouring
global/status
22
Sir Alister Hardy Foundation for Ocean Science
Sea Surface Temperature
1958
2010
Phytoplankton Colour Index
1958
2010
Fig. 13. Long-term trends in Sea Surface Temperature and Phytoplankton Colour
in standard CPR regions of the North Atlantic from 1958-2010.
GACS/status
23
Diatom abundance
1958
2010
Dinoflagellate abundance
1958
2010
Fig. 14. Long-term trends in diatom and dinoflagellate abundance in standard
CPR regions of the North Atlantic from 1958-2010.
global/status
24
Sir Alister Hardy Foundation for Ocean Science
Other anthropogenic pressures
Eutrophication:
Globally, eutrophication is considered a major threat to the
functioning of near-shore ecosystems, as it has been associated
with the occurrence and a perceived increase of harmful algal
blooms (HABs). HABs are in most cases a completely natural
phenomenon having occurred throughout recorded history and
entangling natural bloom events caused by natural hydro-climatic
variability, global climate change and eutrophication is difficult.
For example, increasing temperature, nutrient input fluctuations
in upwelling areas, eutrophication in coastal areas and enhanced
surface stratification all have species specific responses. Prediction
of the impact of global climate change is therefore fraught
with numerous uncertainties. There is some evidence that
biogeographical range extensions caused by regional climate
change has increased the presence of certain HABs in some
regions (Edwards, et al. 2006). Regional climate warming and
hydrographic variability in the North Sea has also been associated
with an increase in certain (HABs) in some areas of the North
Sea particularly along the Norwegian Coastal Current (Edwards,
et al. 2006). The abundance of Prorocentrum spp and Noctiluca
scintillans abundance is strongly correlated with increasing SST
(Hinder, et al. 2012). The increase in a number of diatom species
in the North Sea over the last decade has been associated with
increasing wind intensity (Hinder, et al. 2012). Phenological studies
have also found strong correlations between the movement of
dinoflagellates (up to 1 month earlier) in their seasonal cycle
and regional climate warming (Edwards & Richardson, 2004). In
summary, at the large ecoregional and provincial scale trends in
plankton are associated with hydro-climatic variability. This is not
to say, however, that eutrophication is not a problem and may
in fact be the primary driver in certain coastal regions and at the
more localised scale.
Ocean acidification:
While temperature, light and nutrients are probably the most
important physical variables structuring marine ecosystems,
the pelagic realm will also have to contend with, apart from
global climate warming, the impact of anthropogenic CO2
directly influencing the pH of the oceans. Evidence collected and
modelled to date indicates that rising CO2 has led to chemical
changes in the ocean which has led to the oceans becoming
more acidic. Ocean acidification has the potential to affect the
process of calcification and therefore certain planktonic organisms
(e.g. coccolithophores, foraminifera, pelagic molluscs) may be
particularly vulnerable to future CO2 emissions. Apart from
climate warming, potential chemical changes to the oceans and
their effect on the biology of the oceans could further reduce the
ocean’s ability to absorb additional CO2 from the atmosphere,
which in turn could affect the rate and scale of climate warming.
Presently in the North Atlantic certain calcareous taxa are actually
increasing in terms of abundance, a trend associated with climate
shifts in the Northern Hemisphere temperature. However, there is
some observed evidence from the Southern Ocean that modern
shell weights of foraminifera have decreased compared with much
older sediment core records with acidification being implicated
(Nature Geoscience (2009) doi:10.1038/ngeo460). It is not yet
known how much of an effect acidification will have on the
biology of the oceans in the 21st century, whether rapid climate
warming will override the acidification problem, and whether
or not species can buffer the effects of acidification through
adaptation. The CPR survey is providing a critical baseline (both
in space and time) and is currently monitoring these vulnerable
organisms in case in the future these organisms begin to show
negative effects due to acidification.
Plankton biodiversity and invasive species
At the ocean basin scale biodiversity of phytoplankton are related
to temperature and an increase in warming over the last few
decades has been followed by an increase in diversity particularly
for dinoflagellates and marine copepods (Beaugrand, et al. 2010).
Plankton as a whole show a relationship between temperature
and diversity which is linked to the phytoplankton community
having a higher diversity but an overall smaller size-fraction
and a more complex foodweb structure (i.e microbial-based
versus diatom based production) in warmer more stratified
environments. Climate warming will therefore increase planktonic
diversity throughout the cooler regions of the world’s oceans
as temperature isotherms shift poleward. Apart from thermal
boundaries limits moving progressively poleward and in some
cases expanding, the rapid climate change observed in the Arctic
may have even larger consequences for the establishment of
invasive species and the biodiversity of the North Atlantic. The
thickness and areal coverage of summer ice in the Arctic have
been melting at an increasingly rapid rate over the last two
decades, to reach the lowest ever recorded extent in September
2007. In the spring following the unusually large ice free period in
1998 large numbers of a Pacific diatom Neodenticula seminae were
found in samples taken by the CPR survey in the Labrador Sea
in the North Atlantic. N. seminae is an abundant member of the
phytoplankton in the subpolar North Pacific and has a well defined
palaeo history based on deep sea cores. According to the palaeo
GACS/status
25
evidence and modern surface sampling in the North Atlantic
since 1948 this was the first record of this species in the North
Atlantic for at least 800,000 years. The reappearance of N. seminae
in the North Atlantic, and its subsequent spread southwards and
eastwards to other areas in the North Atlantic, after such a long
gap, could be an indicator of the scale and speed of changes
that are taking place in the Arctic and North Atlantic oceans as a
consequence of climate warming (Reid, et al 2007). The diatom
species could be the first evidence of a trans-Arctic migration in
modern times and be a harbinger of a potential inundation of
new organisms into the North Atlantic. The consequences of such
a change to the function, climatic feedbacks and biodiversity of
Arctic systems are at present unknown.
The copepod species Pseudodiaptomus marinus naturally occurs
in east Asiatic waters but has been subsequently spreading more
widely in the Indo Pacific region over the last decade. The first
record of the species in European waters comes from its discovery
in the Adriatic Sea in 2007. In October 2011 the species was
recorded on CPR routes operating in the southern North Sea (Jha
et al. In prep). The present records extend the known distribution
of P. marinus across the southern Bight from the Netherlands to
the British coast and to the German Bight. It is highly probable the
species presence is due to human activity linked to ballast water
release or aquaculture. The CPR survey will continue to monitor its
Copepod abundance
1958
2010
Copepod mean size
1958
2010
Fig. 15. Long-term trends in copepod abundance and copepod mean size in
standard CPR regions of the North Atlantic from 1958-2010.
global/status
26
Sir Alister Hardy Foundation for Ocean Science
establishment in the North Sea and its probable spread to other
regions.
Summary of plankton and environmental change
Natural variability versus anthropogenic warming: In the North
Atlantic, at the ocean basin scale and over multidecadal periods,
changes in plankton species and communities have been
associated with Northern Hemisphere Temperature (NHT) trends,
the Atlantic Multidecadal Oscillation (AMO), the East Atlantic
Pattern (EAP) and variations in the North Atlantic Oscillation (NAO)
index. It is estimated that 50% of the change is down to natural
climate variability and the other due to forced anthropogenic
warming. These have included changes in species distributions
and abundance, the occurrence of sub-tropical species in
temperate waters, changes in overall plankton biomass and
seasonal length, changes in the ecosystem functioning and
productivity of the North Atlantic (Beaugrand, et al 2003; Edwards,
et al 2001; Edwards, et al, 2002; Reid & Edwards, 2001; Edwards
& Richardson, 2004). Over the last five decades there has been a
progressive increase in the presence of warm-water/sub-tropical
species into the more temperate areas of the North-East Atlantic
and a decline of colder-water species. The mass biogeographical
movements are related to changes in sea surface temperature.
A particularly interesting feature over the last five years is the
decline in subarctic species to the south-east of Iceland and their
movement to the north and west.
a very low winter NAO index. During the last couple of years the
NAO has been uncharacteristically in a very low negative phase
contributing to the very cold winters experienced in Northern
Europe during 2009/2010 and 2010/2011 reflected in below
average SST in the NE Atlantic. Similarly, this has had an effect
on the timing of phenology in the North Sea for many species.
The last couple of years have seen a later seasonality of plankton
compared to the long-term trend which was a trend towards
earlier seasonal cycles (see next section on applied ecological
indicators). While Northern Europe was experiencing cold weather
areas in Greenland, the Canadian Arctic and the Labrador Sea hit
record temperatures in 2010 resulting in extended melt periods.
Between the 1960s and the post 1990s, total Calanus biomass has
declined by 70% due to regional warming. This huge reduction
in biomass has had important consequences for other marine
wildlife in the North Sea including fish larvae.
Biogeographical and phenology indicators: A useful indicator of
the warming trend in the North Sea (a northward shift indicator)
is the percent ratio of the cold-temperate Calanus finmarchicus
and the warm-temperate Calanus helgolandicus copepod species
(see section on applied ecological indicators). Although these
species are very similar they do occupy distinct thermal niches.
The thermal boundary for the arctic-boreal distributed copepod
Calanus finmarchicus in the North-East Atlantic lies between ~1011°C isotherm and is a useful indicator of major biogeographical
provinces. Calanus helgolandicus usually has a northern
distributional boundary of 14°C and has a population optimum
lying between 10-20°C; these two species can therefore overlap in
their distributions.
The percentage ratio between C. helgolandicus and C. finmarchicus
in 2009 to 2011 was for the first time in twenty years dominated
by C. finmarchicus in spring (Fig 16). This was a reflection of the
particularly cold winter experienced in Northern Europe caused by
GACS/status
27
Applied ecological indicators of the NE Atlantic
Marine climate change
impacts
Marine biodiversity
and invasive species
Marine ecosystem and
environmental health
Ocean acidification
Summary for policy makers
global/status
28
Sir Alister Hardy Foundation for Ocean Science
Marine climate change impacts
Biogeographic shifts
Over the last five decades there has been a progressive increase in the
presence of warm-water/sub-tropical species into the more temperate areas
of the North-East Atlantic and a decline of colder-water species. This trend
seems to be accelerating over the last five years. The mass biogeographical
movements are related to changes in sea surface temperature. A particularly
interesting feature over the last five years is the decline in subarctic species
to the south-east of Iceland and their movement to the north and west.
A useful indicator of the warming trend in the North Sea (a northward shift
indicator) is the percent ratio of the cold-temperate Calanus finmarchicus
and the warm-temperate Calanus helgolandicus copepod species. Although
these species are very similar they do occupy distinct thermal niches.
The thermal boundary for the arctic-boreal distributed copepod Calanus
finmarchicus in the North-East Atlantic lies between ~10-11°C isotherm
and is a useful indicator of major biogeographical provinces. Calanus
helgolandicus usually has a northern distributional boundary of 14°C and
has a population optimum lying between 10-20°C; these two species can
therefore overlap in their distributions. When these two species co-occur
there is a tendency for high abundances of C. finmarchicus earlier in the
year and C. helgolandicus later in the year. There is clear evidence of thermal
niche differentiation between these two species as well as successional
partitioning in the North Sea, probably related to cooler temperatures earlier
in the year and warmer temperatures later in the year.
Calanus finmarchicus
Calanus helgolandicus
The percentage ratio between C. helgolandicus and C. finmarchicus
between 2009 and 2010 was for the first time in twenty years dominated
by C. finmarchicus in spring. This was a reflection of the particularly cold
winter experienced in Northern Europe caused by a very low winter NAO
index. Between the 1960s and the post 1990s, total Calanus biomass
has declined by 70%. This huge reduction in biomass has had important
consequences for other marine wildlife in the North Sea including fish
larvae larvae.
Fig. 16. A simple ratio between a warm-water species (Calanus
helgolandicus) and a cold-water species (Calanus finmarchicus)
per month from 1958-2010. Red values indicate a dominance of
the warm-water species and blue values the dominance of the
cold-water species. (0= total C. finmarchicus dominance, 1=total
C. helgolandicus dominance)
GACS/status
29
a. Biogeographical
Warm-temperate
species
Temperate
species
Cold-temperate
species
Phenology
Subarctic
species
5
11.5
Echinoderm phenology and annual mean SST
5.5
11
Seasonal peak (months)
6
10.5
6.5
10
7
9.5
7.5
9
8
September
1000 km
shift northward
Sea Surface Temperature
May
Phenology - the study of natural phenomena that recur periodically, as migration or blossoming,
and of their relation to climate and changes in season. Seasonal timing, or phenology, is occurring
earlier in the North Sea and is related to regional climate warming. For example, some species
have moved forward in their seasonal cycle by 4-5 weeks. However, not all trophic levels are
responding to the same extent, therefore in terms of a productive environment, this change is
considered detrimental because of the potential of mis-timing (mismatch) of peak occurrences
of plankton with other trophic levels including fish larvae. There is a high confidence that these
trends are related to regional climate warming. In particular, the trend towards an earlier seasonal
appearance of meroplanktonic larvae over the last few decades is highly correlated with sea
surface temperature. The trend in 2010, however, was later than the previous years due to the cold
winter experienced in Northern Europe.
8.5
8.5
9
8
1958
1968
1978
1988
1998
2008
Years
Fig. 17. Biogeographical changes in plankton assemblages spanning five
decades. Warm-water plankton (e.g. warm-temperate species) are moving north
and cold-water plankton (e.g. subarctic species) are moving out of the North
Sea. Based on Science (2002) 296: 1692-1694.
Fig. 18. Phenological shifts in echinoderm larvae and mean annual SST in
the North Sea from 1958-2010. The main decadal trend is towards an earlier
seasonal cycle, however, the year 2010 was later than the previous years. Based
on Nature (2004) 430: 881-884.
global/status
30
Sir Alister Hardy Foundation for Ocean Science
Marine biodiversity and invasive
species
Total oceanic diversity
(Gini diversity)
Multi-decadal trends in ocean biodiversity
Long-term latitudinal changes
in species diversity
At the ocean basin scale studies on the pelagic biodiversity of zooplankton copepods
are related to temperature and an increase in warming over the last few decades has
been followed by an increase in diversity. There is also a direct link between diversity
and the size-structure of the zooplankton community. The overall diversity patterns
of pelagic organisms, peaking between 20° to 30° north or south, follow temperature
gradients in the world’s oceans. Similarly, phytoplankton show a relationship between
temperature and diversity which is linked to the phytoplankton community having
a higher diversity but an overall smaller size-fraction and a more complex foodweb
structure (i.e. microbial-based versus diatom-based production) in warmer, more
stratified environments. The parallel decrease in size-structure of pelagic organisms
with increasing diversity may have implications for marine ecosystem services such
as smaller-sized fish communities and reduced carbon drawdown (PNAS (2010) 107:
10120-10124).
Mean residence time of
particulate carbon
Long-term latitudinal
changes in carbon
residence time
Fig. 19. Relationships between the spatial distribution and long-term latitudinal changes
in the diversity and a size-derived functional characteristic of calanoid copepods in the
extratropical North Atlantic. Diversity was measured by first-order jackknife performed on the
Gini coefficient. Left panel: mean spatial distributions (1960-2007) of copepod diversity and
mean residence time above 50 m of sinking copepod particles (in days). Right panel: longterm latitudinal changes in copepod diversity and mean residence time above 50 m of sinking
copepod particles. Based on (PNAS (2010) 107: 10120-10124).
GACS/status
31
Invasive species
Because of its extensive geographical coverage and long time frame, data from the CPR have provided invaluable information on
the spread of non-native plankton. For example, the invasive diatom Coscinodiscus wailesii, which has become a persistent and
significant member of the plankton community, has spread from its first record off Plymouth in 1977 throughout all coastal waters
of northern Europe and out into the Atlantic in a matter of only 30 years.
A recent review of non-native marine species around the British Isles that includes plankton and HAB species provides more detail
on planktonic introductions. The discovery of the comb jelly Mnemiopsis leidyi in North Sea waters is of particular concern, even
though it has not yet been recorded in the British Isles, because of the very marked impact it appears to have had on fisheries and
the general ecosystem when it has appeared in other parts of the world.
Climate warming will open up new thermally defined habitats (see section on habitat expansion of temperate province) for previously denied non-indigenous species (e.g. sub-tropical species in the North Sea) and invasive species allowing them to establish
viable populations in areas that were once environmentally unsuitable. Apart from these thermal boundary limits moving progressively poleward and in some cases expanding, the rapid climate change observed in the Arctic may have even larger consequences
for the establishment of invasive species and the biodiversity of the North Atlantic (see figure 20 left).
New copepod species found in the southern North Sea
Fig. 20. It has recently been highlighted that Arctic ice is reducing faster
than previous modelled estimates. As a consequence the biological
boundaries between the North Atlantic Ocean and Pacific may become
increasingly blurred with an increase of trans-Arctic migrations becoming
a reality. The CPR survey has already documented the presence of a
Pacific diatom, Neodenticula seminae, in the Labrador Sea since the late
1990s which has since spread southwards and eastwards. The diatom
species itself has been absent from the North Atlantic for over 800,000
years and could be the first evidence of a trans-Arctic migration in
modern times and be the harbinger of a potential inundation of new
organisms to the North Atlantic. The consequences of such a change to
the function and biodiversity of Arctic systems are at present unknown.
Total records (blue), records in 2010 (red).
More information: Global Change Biology (2007)13: 1910-1921
A new invasive copepod species has been found in the North Sea. The copepod species Pseudodiaptomus marinus naturally occurs
in east Asiatic waters but has been subsequently spreading more widely in the Indo Pacific region over the last decade. The first
record of the species in European waters comes from its discovery in the Adriatic Sea in 2007. In October 2011 the species was
recorded on CPR routes operating in the southern North Sea (Jha et al. In prep). The present records extend the known distribution
of P. marinus across the southern Bight from the Netherlands to the British coast and to the German Bight. It is highly probable the
species presence is due to human activity linked to ballast water release or aquaculture. The CPR survey will continue to monitor its
establishment in the North Sea and its probable spread to other regions.
Unusual biodiversity records in 2010/11
Two rare species of calanoid copepods from the North Atlantic were found in 2010: last recorded in 1974, Euchirella amoena was
found in July in the middle of the subtropical Atlantic and off the coast of New York; on the same coastal sample a Scaphocalanus
echinatus was also identified. Although not unusual in their distribution these copepods are scarce in the CPR survey having
only previously been recorded 3 and 19 times respectively. Similar in size to the aforesaid copepods, Calanus finmarchicus is
contrastingly one of the most abundantly found copepods on North Atlantic CPR samples and is associated with the Atlantic polar
biome. However, in March 2010 there were 2 occurrences of C. finmarchicus in oceanic subtropical waters. During the last 30 years
C. finmarchicus has only been identified 8 times in this region and is typically replaced by its warmer-water-loving sister species C.
helgolandicus. Calanus species are important food items for higher marine animals including fish. Pacillina arctica incertae sedis, an
organism of uncertain taxonomic placement, was recorded in July 2010 stretching some 80 miles along the coastline of New York.
These are the most westerly sightings ever of this suspected ciliate cyst in the CPR survey.
global/status
32
Sir Alister Hardy Foundation for Ocean Science
Marine ecosystem and
environmental health
Eutrophication and Habs
There has been a considerable increase in phytoplankton biomass (Phytoplankton Colour Index) over the last decade in certain regions of
the North-East Atlantic and North Sea, particularly over the winter months. Increased phytoplankton biomass may be an indicator of eutrophication; however, similar patterns of change have been found in both coastal and offshore waters. In the North Sea a significant increase
in phytoplankton biomass has been found in both heavily anthropogenically-impacted coastal waters and the comparatively less-affected
open North Sea despite significantly decreasing trends in nutrient concentrations. The increase in biomass appears to be linked to warmer
temperatures and evidence that the waters are also becoming clearer (i.e. less turbid), thereby allowing the normally light-limited coastal
phytoplankton to more effectively utilise lower concentrations of nutrients (Limnology and Oceanography (2007) 52: 635–648). These results
may indicate that climatic variability and water transparency may be more important than nutrient concentrations to phytoplankton production in the North Sea. Despite the overriding influence of climate, elevated nutrient levels may be of concern in some localised areas around
European seas. In general, HABs are naturally occurring events although some exceptional blooms have been associated with eutrophication
in coastal waters. HAB taxa are generally most numerous along the Dutch coast and off the northern Danish coast. In particular the red-tide
forming species Noctiluca scintillans naturally forms extensive blooms during the summer period in these areas as well as in the Irish Sea.
Large HABs during 2010 occurred within the range of natural variability and were similar to the long-term average occurrences. However,
the large blooms of Pseudo-nitchia spp. that occurred in the southern North Sea were particularly numerous in 2010 and are becoming more
common in the North Sea over the last decade.
Fig. 21. The distribution of large HAB blooms in Northern
European waters in 2010. Large or exceptional HAB blooms
are equivalent to 4 standard deviations above the long-term
mean (1958-2009).
Trends in marine pathogens
As sea surface temperatures increase, predictions favour an increase in number and range of pathogenic micro-organisms. Such
changes are difficult to determine over short time periods that cannot separate short-term variations from climate change trends. In
a unique long-term time study, Vezzulli et al. (2011) investigated the spread of the pathogenic bacteria, Vibrio, the causative agent of
cholera in the North sea over 54 years, between 1961-2005, and revealed that Vibrio bacteria are increasing in this region. The VAI was
found to steadily increase over four decades which was linked to temperature and copepod abundance but not PCI. The Rhine area
was significantly correlated with VAI, which has higher summer SST over 18˚C, where Vibrio thrives best (Vezzulli et al. 2004), and was
especially marked in the late 1980s when step-wise increase in SST was reported in the Southern North Sea. No significant increase
was found in the Humber, which never exceeds 18˚C. Vibrio attaches to chitin surfaces, so the relationship with Copepods, may reveal
the mechanism by which this pathogen spreads.
Marine microplastics
From the presence of microplastics that have been recorded on CPR samples it is clear that microplastics are widely distributed in the
North-East Atlantic with the frequency of microplastics increasing towards the coasts (particularly in the southern North Sea). From
retrospective analysis of some CPR samples spanning three decades it appears that microplastics are increasing in frequency through
time (Science (2004) 308:834). The incidence of monofilament netting snagged by the CPR towed body also seems to be increasing,
particularly in the southern North Sea.
GACS/status
33
Fig. 22. The geographical distribution of microplastics
recorded on CPR samples in 2010 and between 20042009. While the distribution largely reflects CPR sampling
frequency it does show that microplastics are widely
distributed in the North Atlantic including the offshore
oceanic environment.
Ocean acidification
10
9
Changes in temperature have direct consequences on many physiological processes (e.g. oxygen
metabolism, adult mortality, reproduction, respiration, reproductive development) and control
virtually all life-processes from the molecular to the cellular and from the regional ecosystem level
to biogeographical provinces. Temperature also modulates species interactions (e.g. competition,
prey-predator interactions and foodweb structures) both directly and indirectly; ultimately, changes in
temperatures caused by climate change can lead to impacts on the biodiversity, size structure, carrying
capacity and functioning of the whole pelagic ecosystem. While temperature has direct consequences
on many biological and ecological traits it also modifies the marine environment by influencing
oceanic circulation and by enhancing the stability of the water column and hence nutrient availability.
Under many climate change scenarios, oceanic primary production is predicted to decline due to
nutrient limitation.
Percent frequency
8
7
6
5
4
3
2
1
0
1958 1963 1968 1973 1978 1983 1988 1993 1998 2003 2008
Years
Fig. 23. The percent frequency of foraminifera recorded on
CPR samples
While temperature, light and nutrients are probably the most important physical variables structuring
marine ecosystems, the pelagic realm will also have to contend with, apart from global climate
warming, the impact of anthropogenic CO2 directly influencing the pH of the oceans. Evidence
collected and modelled to date indicates that rising CO2 has led to chemical changes in the ocean
which has led to the oceans becoming more acidic. Ocean acidification has the potential to affect the
process of calcification and therefore certain planktonic organisms (e.g. coccolithophores, foraminifera,
pelagic molluscs) may be particularly vulnerable to future CO2 emissions. Apart from climate warming,
potential chemical changes to the oceans and their effect on the biology of the oceans could further
reduce the ocean’s ability to absorb additional CO2 from the atmosphere, which in turn could affect the
rate and scale of climate warming.
Presently in the North Atlantic certain calcareous taxa are actually increasing in terms of abundance,
a trend associated with climate shifts in the Northern Hemisphere temperature (see above figure of
foraminifera frequency). However, there is some observed evidence from the Southern Ocean that
modern shell weights of foraminifera have decreased compared with much older sediment core
records with acidification being implicated (Nature Geoscience (2009) doi:10.1038/ngeo460). It is not yet
known how much of an effect acidification will have on the biology of the oceans in the 21st century,
whether rapid climate warming will override the acidification problem, and whether or not species can
buffer the effects of acidification through adaptation. The CPR survey is providing a critical baseline
(both in space and time) and is currently monitoring these vulnerable organisms in case in the future
these organisms begin to show negative effects due to acidification.
global/status
34
Sir Alister Hardy Foundation for Ocean Science
Summary for policy makers
Marine climate change impacts: Northward shifts
Warmer-water species are currently increasing in the North Sea due to regional climate warming and the NAO. In terms
of a productive environment this change is currently considered detrimental because the warmer-water species are not
replacing the colder-water species in similar abundances which may negatively impact other trophic levels including
fish larvae. For example, an important zooplankton species has declined by 70 % in the North Sea. There is a high
confidence that these trends are related to regional climate warming.
Marine climate change impacts: Changes in seasonality and phenology
Seasonal timing, or phenology, is occurring earlier in the North Sea and is related to regional climate warming. For
example, some species have moved forward in their seasonal cycles by 4-5 weeks. However, not all trophic levels are
responding to the same extent; therefore in terms of a productive environment, this change is currently considered
detrimental because of the potential of mis-timing (mismatch) of peak occurrences of plankton with other trophic levels
including fish larvae. There is a high confidence that these changes are associated with regional climate warming.
Marine biodiversity and invasive species
Oceanic plankton biodiversity is increasing in the North Atlantic associated with temperature increases. There is a strong
relationship between biodiversity and size-structure in pelagic communities. Increasing biodiversity is associated with
a decreasing size-structure of the community. This in turn may have implications for marine ecosystem services such as
smaller-sized fish communities and reduced carbon drawdown.
Marine ecosystem health and water quality
At the regional scale, it has been found that most phytoplankton trends are related to hydro-climatic variability as
opposed to anthropogenic input (e.g. nutrient input leading to eutrophication). This means that the North-East Atlantic
as a whole is generally considered to be fairly healthy. This is not to say, however, that certain coastal areas and the
southern North Sea are not vulnerable to eutrophication and climate change may also exacerbate these negative
effects in these vulnerable regions. It has also been found that the number of microplastics collected on CPR samples
is increasing and the frequency of occurrence and bloom timing of some Harmful Algal Bloom species are related to
regional climate warming.
Ocean acidification
Organisms that could be particularly vulnerable to acidification are the calcifying organisms such as coccolithophores
and foraminifera. The CPR survey is proving a critical baseline and is currently monitoring these vulnerable organisms
in case these organisms start to show any negative effects due to acidification in the future. Over the last few decades
trends in calcifying organisms recorded by the CPR survey have been correlated with changes in Northern Hemisphere
Temperatures rather than changing pH. However, acidification may become the main driver of change in the future.
GACS/status
35
Bibliography
Aoki, S., Yoritaka, M., Masuyama, A. (2003) Multidecadal warming of subsurface temperature in the Indian sector of the Southern Ocean, J. Geophys. Res., 108, 8081, doi:10.1029/2000JC000307.
Arzel, O., Fichefet, T., Goosse, H. (2006) Sea ice evolutions over the 20th and 21st centuries as simulated by current AOGCMs. Ocean Model. 12, 401-415
Atkinson, A., Siegel, V., Pakhomov, E., Rothery, P. (2004) Long-term decline in krill stock and increase in salps within the Southern Ocean. Nature, 432, 100-103.
Atkinson, A., Siegel, V., Pakhomov, E.A., Rothery, P., Loeb, V., Ross, R.M., Quetin, L.B., Schmidt, K., Fretwell, P., Murphy, E.J., Tarling, G.A., Fleming, A.S., (2008) Oceanic circumpolar habitats of Antarctic krill. Mar.
Ecol. Prog. Ser. 362, 1–23.
Atkinson, A., Sinclair, J.D., (2000) Zonal distribution and seasonal vertical migration of copepod assemblages in the Scotia Sea. Polar Biol. 23, 46–58.
Batten, S.D., and Mackas, D.L. (2009) Shortened duration of the annual Neocalanus plumchrus biomass peak in the Northeast Pacific. Marine Ecology Progress Series. 393, 189-198.
Batten, S.D and Walne, A.W. (2011) Variability in northwards extension of warm water copepods in the NE Pacific. Journal of Plankton Research 33, 1643-1653
Batten, S.D., Walne, A.W., Edwards, M. and Groom, S. B. (2003) Phytoplankton biomass from Continuous Plankton Recorder data: An assessment of the phytoplankton colour index. Journal of Plankton
Research 25, 697-702.
Beaugrand G, Reid PC, Ibanez F, Lindley JA, Edwards M (2002) Reorganization of North Atlantic Marine Copepod Biodiversity and Climate. Science 296:1692-1694
Beaugrand G, Edwards, M, Brander K, Luczaki C, Ibenez F. (2008) Causes and projections of abrupt climate-driven ecosystem shifts in the North Atlantic. Ecology Letters 11: 1157-1168
Beaugrand G, Edwards, M, Legendre L. (2010) Marine biodiversity, ecosystem functioning, and carbon cycles. PNAS 107: 10120–10124.
Behrenfeld MJ, O’Malle RT, Siegel DA, McClain CR, Sarmiento JL, Feldman GC, Milligan AJ, Falkowski PG Ricardo Letelier M, Boss ES. (2006) Climate-driven trends in contemporary ocean productivity. Nature
444: 752-755.
Bracegirdle, T.J., Connolley, W.M., Turner, J. (2008) Antarctic climate change over the 21st century. J. Geophys. Res. 113, D03103. doi:10.1029/2007JD008933
Chiba, S., Ishimaru, T., Hosie, G., Fukuchi, M. (2001) Spatio-temporal variability of zooplankton community structure off east Antarctica (90º to 160ºE). Marine Ecology Progress Series, 216, 95–108.
Chiba S, Tadokoro K, Sugisaki H, Saino T (2006) Effects of decadal climate change on zooplankton over the last 50 years in the western subarctic North Pacific. Global Change Biology 12(5): 907-920.
Chiba S, S. Batten, K. Sasaoka, H. Sugisaki (2012) Influence of the Pacific Decadel Oscillation on phytoplankton phenology and community structure in the western North Pacific based on satellite observation
and the Continuous Plankton Recorder survey for 2001–2009. Geophysical Research Letters. Vol. 39, L15603, doi:10.1029/2012GL052912
Cubillos, J.C., Wright, S.W., Nash, G., de Salas, M.F., Griffiths, B., Tilbrook, B., Poisson, A., Hallegraeff, G.M. (2007) Calcification morphotypes of the coccolithophorid Emiliania huxleyi in the Southern Ocean:
changes in 2001 to 2006 compared to historical data. Marine Ecology-Progress Series, 348, 47-54.
de la Mare, W.K. (2009) Changes in Antarctic sea-ice extent from direct historical observations and whaling records. Climate Change, 92, 461-493
Dinniman, M.S., Klinck, J.M. and Hofmann, E.E. (2012) Sensitivity of Circumpolar Deep Water transport and ice shelf basal melt along the west Antarctic Peninsula to changes in the winds. Journal of Climate.
doi: http://dx.doi.org/10.1175/JCLI-D-11-00307.1
global/status
36
Sir Alister Hardy Foundation for Ocean Science
Ducklow, H.W., Baker, K., Martinson, D.G., Quetin, L.B., Ross, R.M., Smith, R.C., Stammerjohn, S.E., Vernet, M., Fraser, W. (2007) Marine pelagic ecosystems: the West Antarctic Peninsula. Philosophical Transactions
of the Royal Society of London B 362:67-94
Edwards M, Beaugrand G, Reid PC, Rowden AA, Jones MB (2002) Ocean climate anomalies and the ecology of the North Sea. Marine Ecology-Progress Series 239:1-10
Edwards M, Johns DG, Leterme SC, Svendsen E, Richardson AJ (2006) Regional climate change and harmful algal blooms in the northeast Atlantic. Limnol Oceanogr 51:820-829
Edwards M, Reid P, Planque B (2001) Long-term and regional variability of phytoplankton biomass in the Northeast Atlantic (1960-1995). ICES J Mar Sci 58:39-49
Edwards M, Richardson AJ (2004) Impact of climate change on marine pelagic phenology and trophic mismatch. Nature 430:881-884
Gille, S.T. (2002) Warming of the Southern Ocean Since the 1950s. Science 295,1275-1277.
Hardy, A.C., Gunther, E.R., (1935) The plankton of the South Georgia whaling grounds and adjacent waters 1926–1927. Discovery Report 11, 1–456.
Harrison, P.J., Boyd, P.W., Varela, D.E., Takeda, S., Shiomoto, A. and Odate, T. 1999. Comparison of factors controlling phytoplankton productivity in the NE and NW subarctic Pacific gyres. Progress in
Oceanography, 43, 205-234.
Hinder SL, Manning J.E., Gravenor, M.B., Edwards, M., Walne, A.W., Burkhill, P. H., Hays, G.C. (2011 ) Long-term changes in abundance and distribution of microzooplankton in the NE Atlantic and North Sea.
Journal of Plankton Research.
Hinder SL, Hays GC, Edwards M, Roberts EC, Walne AW, Gravenor MB (2012) Changes in marine dinoflagellates and diatom abundance under climate change. Nature Climate Change 12: 1-5.
Hofmann, E.E., Wiebe, P.H., Costa, D.P. and Torres, J.J. (2008) Introduction to dynamics of plankton, krill, and predators in relation to environmental features of the western Antarctic Peninsula and related areas:
SO GLOBEC Part II. Deep-Sea Research II 55:269-270.
Holm-Hansen, O., Kahru,M., Hewes,C.D., Kawaguchi,S., Kameda,T., Sushin,V.A., Krasovski, I., Priddle,J., Korb,R., Hewitt,R.P., Mitchell,B.G., (2004)Temporal and spatial distribution of chlorophyll-a in surface waters
of the Scotia Sea as determined by both shipboard measurements and satellite data. Deep-Sea Research II 51,1323–1331
Hosie, G.W., Cochran T.G. (1994) Mesoscale distribution patterns of macrozooplankton communities in Prydz Bay, Antarctica - January to February 1991. Marine Ecology Progress Series 106, 21-39
Hosie, G.W., Fukuchi, M. and Kawaguchi, S. (2003) Development of the Southern Ocean Continuous Plankton Recorder Survey. Progress in Oceanography 58 (2-4), 263-283
Hosie, GW, Schultz, MB, Kitchener, JA, Cochran, TG, Richards, K (2000) Zooplankton community structure off East Antarctica (80-150° east) during the Austral summer of 1995/96. Deep Sea Research 47, No.
12-13, 2437-2463
Hunt, B. P. V., Pakhomov, E. A., Hosie, G. W., Siegel, V., Ward, P. Bernard, K. (2008) Pteropods in Southern Ocean ecosystems. Progress in Oceanography 78, 193-221
Hunt, B.P.V., Hosie, G.W. (2005) Zonal structure of zooplankton communities in the Southern Ocean South of Australia: results from a 2150 km continuous plankton recorder transect. Deep-Sea Research Part I,
52, 1241-1271.
Hunt, B.P.V., Hosie, G.W. (2006a) The seasonal succession of zooplankton in the Southern Ocean south of Australia, part I: the seasonal ice zone. Deep Sea Research I, 53, 1182-1202.
Hunt, B.P.V., Hosie, G.W. (2006b) The seasonal succession of zooplankton in the Southern Ocean south of Australia, part II: the sub-antarctic to Polar Frontal Zones. Deep Sea Research I, 53, 1203-1223.
Ishikawa, A., Wright, S.W., van den Enden, R., Davidson, A.T. and Marchant, H.J. (2002). Abundance, size structure and community composition of phytoplankton in the Southern Ocean in the austral summer
1999/2000. Polar Biosciences 15: 11-26.
GACS/status
37
Jacques, G., Panouse, M., (1991) Biomass and composition of size fractionated phytoplankton in the Weddell–Scotia confluence area. Polar Biology 11, 315–328.
Johns DJ, Edwards M, Batten S (2001) Arctic boreal plankton species in the Northwest Atlantic. Canadian Journal of Fisheries and Aquatic Sciences 58:2121-2124
Loeb, V., Hofmann, E.E., Klinck, J.M., Holm-Hansen, O. (2010) Hydrographic control of the marine ecosystem in the South Shetland-Elephant Island and Bransfield Strait region. Deep-Sea Research II, 57: 519542.
Longhurst. 2001. Ecological Geography of the Sea. Academic Press
McClintock, J., Ducklow, H., Fraser, W. (2008) Ecological Responses to Climate Change on the Antarctic Peninsula. American Scientist 96:302- 310.
Mackey, A., Atkinson,A., Hill,S., Ward,P., Cunningham,N., Johnston,N.M., Murphy, E.J., (2012) Antarctic macrozooplankton of the south west Atlantic sector and Bellingshausen Sea: baseline historical
distributions (Discovery Investigations, 1928–1935) related to temperature and food, with projections for subsequent ocean warming. Deep-Sea Res. II 59–60,130–146.
Mackas, D.L., Batten, S.D., and Trudel, M., (2007) Effects on zooplankton of a warming ocean: recent evidence from the Northeast Pacific. Progress in Oceanography, 75, 223-252
Mackintosh, N.A., (1934) Distribution of the macroplankton in the Atlantic sector of the Antarctic. Discovery Rep. 9, 65–160.
McLeod, D., Hallegraeff, G., Hosie, G., Richardson, A. (2012) Climate-driven range expansion of the red-tide dinoflagellate Noctiluca scintillans into the Southern Ocean. Journal of Plankton Research, 34, 332337.
McLeod, D.J., Hosie, G.W., Kitchener, J.A., Takahashi, K.T., Hunt, B.P.V. (2010) Zooplankton Atlas of the Southern Ocean: The Southern Ocean Continuous Plankton Recorder Survey (1991-2008) Polar Science 4
(2), 353-385 10.1016/j.polar.2010.03.004
Marchant, H., Davidson, A., Wright, S. (1987) The distribution and abundance of chroococcoid cyanobacteria in the Southern Ocean. Proceedings of the NIPR Symposium on Polar Biology, 1, 1-9.
Massom, R.A., Stammerjohn, S.E. (2010) Antarctic sea ice change and variability - Physical and ecological implications. Polar Sciences 4, 149-186
McKinnel, S.M and Dagg, M.J. [Eds.} 2010. Marine Ecosystems of the North Pacific Ocean, 2003-2008. PICES Special Publication 4, 393 p.
Meskhidze, N., Nenes, A., Chameides, W.L., Luo, C., Mahowald, N., (2007) Atlantic Southern Ocean productivity: fertilization from above or below? Global Biogeochemical Cycles 21, GB2006.
doi:10.1029/2006GB002711.
Miller CB, Frost BW, Batchelder HP, Clemons MJ, Conway RE (1984) Life histories of large, grazing copepods in a subarctic ocean gyre: Neocalanus plumchrus, Neocalanus cristatus, and Eucalanus bungii in the
Northeast Pacific. Prog Oceanogr, 13:201-243.
Mohan, R., Mergulhao, L.P., Guptha, M.V.S., Rajakumar, A., Thamban, M., Anil Kumar, N., Sudhakar, M., Ravindra, R. (2008) Ecology of coccolithophores in the Indian sector of the Southern Ocean. Marine
Micropaleontology 67, 30-45
Montes-Hugo, M., Doney, S.C., Ducklow, H.W., Fraser, W., Martinson, D., Stammerjohn, S.E., Schofield, O. (2009) Recent Changes in Phytoplankton Communities Associated with Rapid Regional Climate Change
Along the Western Antarctic Peninsula. Science, 323, 1470-1473
Moy, A.D., Howard, W.R., Bray, S.G., Trull, T.W. (2009) Reduced calcification in modern Southern Ocean planktonic foraminifera. Nature Geoscience, 2, 276-280.
Orr, J.C., Fabr, V.J., Aumont, O., Bopp, L., Doney, S.C., Feely, R.A., Gnanadesikan, A., Gruber, N., Ishida, A., Joos, F., Key, R.M., Lindsay, K., Maier-Reimer, E., Matear, R., Monfray, P., Mouchet, A., Najjar, R.G., Plattner,
G.K., Rodgers, K.B., Sabine, C.L., Sarmiento, J.L., Schlitzer, R., Slater, R.D., Totterdell, I.J., Weirig, M.F. Yamanaka, Y. Yool. A. (2005) Anthropogenic ocean acidification over the twenty-first century and its impact on
calcifying organisms. Nature, 437, 681-686.
global/status
38
Sir Alister Hardy Foundation for Ocean Science
Pane, L., Feletti, M., Francomacaro, B. Mariottini, G.L. (2004) Summer coastal zooplankton biomass and copepod community structure near the Italian Terra Nova Base (Terra Nova Bay, Ross Sea, Antarctica).
Journal of Plankton Research, 26, 1479-1488
Park, J.,Oh,I.-S.,Kim,H.-C.,Yoo,S.,2010.Variability of SeaWiFS chlorophyll a in the southwest Atlantic sector of the Southern Ocean: strong topographic effects and weak seasonality. Deep-Sea Research I
57,604–620.
Pinkerton, M., Smith, A.N., Raymond, B., Hosie, G.W., Sharp, B., Leathwick, J.R. and Bradford-Grieve, J.M. (2010) Spatial and seasonal distribution of adult Oithona similis in the Southern Ocean: predictions
using boosted regression trees. Deep-Sea Research I 57, 469–485
Raitsos DE, Reid PC, Lavender S, Edwards M. Richardson, AJ. (2005) Extending the SeaWiFS chlorophyll data set back 50 years in the northeast Atlantic. 32: 1-4.
Reid PC, Johns DG, Edwards M, Starr M, Poulin M, Snoeijs P (2007) A biological consequence of reducing Arctic ice cover: arrival of the Pacific diatom Neodenticula seminae in the North Atlantic for the first
time in 800 000 years. Global Change Biology 13: 1910–1921
Reid PC, Edwards M (2001) Long-term changes in the pelagos, benthos and fisheries of the North Sea. Marin Biodiversity 31:107-115
Richardson AJ. Shoeman DS. (2004) Climate Impact on Plankton Ecosystems in the Northeast Atlantic. Science 305: 1609-1612
Richardson AJ, Walne AW, John AWGJ, Jonas TD, Lindley JA, Sims DW, Stevens D, Witt M (2006) Using continuous plankton recorder data. Prog Oceanogr 68:27-74.
Royal Society. (2005) Ocean acidification due to increasing atmospheric carbon dioxide. Policy document 12/05. The Royal Society, London. 60 pp, http://royalsociety.org/Ocean-acidification-duetoincreasing-atmospheric-carbon-dioxide/
Smith Jr, K.L., Robison, B.H., Helly, J.J., Kaufmann, R.S., Ruhl, H.A., Shaw, T.J., Twining, B.S., Vernet, M., (2007) Free-drifting icebergs: hotspots of chemical and biological enrichment in the Weddell Sea. Science
317, 478–482.
Swadling, K.M., Kawaguchi, S., Hosie, G.W. (2010) Antarctic mesozooplankton community structure during BROKE-West (30°E – 80°E), January – February 2006. Deep-Sea Research II. 57, 887-904
Takahashi, K., Hosie, G., Kitchener, J., Mcleod, D., Odate, T., Fukuchi, M. (2010a) Comparison of zooplankton distribution patterns between four seasons in the Indian Ocean sector of the Southern Ocean. Polar
Science, 4, 317-331.
Takahashi, K., Tanimura, A., Fukuchi, M. (1998) Long-term observation of zooplankton biomass in the Indian Ocean sector of the Southern Ocean. In: Proceedings of the International Symposium on
Environmental Research in Antarctica. Memoirs of the National Institute of Polar Research. Spec. Issue 52, 209-219
Takahashi, K.T., Kawaguchi, S., Hosie, G.W., Toda, T., Naganobu, M. and Fukuchi, M. (2010) Surface zooplankton distribution in the Drake Passage recorded by Continuous Plankton Recorder (CPR) in late austral
summer of 2000. Polar Science 3, 235-245
Urrutxurtu I (2004) Seasonal succession of tintinnids in the Nervio´n River estuary, Basque Country, Spain. Journal of Plankton Research 26: 307-314.
Verity, P. G. (1987) Abundance, community composition, size distribution, and production rates of tintinnids in Narragansett Bay,Rhode Island. Estuarine Coastal Shelf Sci., 24, 671–690.
Vezzulli L, Brettar, I., Pezzati, E., Reid, P.C.,Colwell, R.R., Hofle, M.G., Pruzzo, C. (2011) Long-term effects of ocean warming on the prokaryotic community: evidence from the vibrios. ISME Journal 6: 21-30.
Vuorinen, I., Hänninen, J., Bonsdorff, E., Boormann, B., Angel, M.V., (1997) Temporal and spatial variation of dominant pelagic Copepoda (Crustacea) in the Weddell Sea (Southern Ocean) 1929 to 1993. Polar
Biology 18, 280–291.
Ward, P., Atkinson, A., Tarling, G.A, (2012) Mesozooplankton community structure and variability in the Scotia Sea: a seasonal comparison. Deep-Sea Res. II 59–60, 78–92.
GACS/status
39
Ward, P., Grant, S., Brandon, M.A., Siegel, V., Sushin, V., Loeb, V., Griffiths, H., (2004) Mesozooplankton community structure in the Scotia Sea during the CCAMLR 2000 survey: January–February 2000. Deep-Sea
Res. II 51, 1351–1367.
Ward, P., Meredith, M.P., Whitehouse, M.J., Rothery, P., (2008). The summertime plankton community at South Georgia (Southern Ocean): Comparing the historical (1926/1927) and modern (post 1995) records.
Progress in Oceanography 78, 241–256.
Ward, P., Shreeve, R., Atkinson, A., Korb, R., Whitehouse, M., Thorpe, S., Pond, D., Cunningham, N., (2006) Plankton community structure and variability in the Scotia Sea: austral summer 2003. Mar. Ecol. Prog.
Ser. 309, 75–91.
Warner AJ, Hays, GC. (1994). Sampling by the Continuous Plankton Recorder survey. Progress in Oceanography 34: 237-256.
Whitehouse, M.J., Atkinson, A., Korb, R.E., Venables, H.J., Pond, D.W., Gordon, M., (2012) Substantial primary production in the land-remote region of the central and northern Scotia Sea. Deep-Sea Research II
59–60, 47–56.
global/status
40
Sir Alister Hardy Foundation for Ocean Science
GACS/status
41
The Sir Alister Hardy Foundation for Ocean
Science (SAHFOS) is an internationally
funded charity (Canada, Norway, UK and the
USA) that operates the Continuous Plankton
Recorder (CPR) survey. The Foundation
has been collecting data from the North
Atlantic and the North Sea on biogeography
and ecology of plankton since 1931. More
recently, work has been expanded to include
other regions around the globe including
the Arctic and Southern Ocean. The results
of the survey are used by marine biologists,
scientific institutes and in environmental
change studies across the world. The SAHFOS
team is based in Plymouth, England and
consists of analysts, technicians, researchers
and administrators, who all play an integral
part in the running of the survey.
SAHFOS
The Laboratory, Citadel Hill
Plymouth, PL1 2PB, UK
Tel: +44(0)1752-633288
Fax: +44(0)1752-600015
Email: sahfos@sahfos.ac.uk
Web: www.sahfos.org
global/status
42
Sir Alister Hardy Foundation for Ocean Science